#define INF 4'000'000'000'000'000'037LL #define EPS 1e-11 #include using namespace std; using ld = decltype(EPS); using ll = long long; using uint = unsigned int; using ull = unsigned long long; using pll = pair; using tlll = tuple; using tllll = tuple; #define vc vector template using vvc = vc>; using vpll = vc; using vstr = vc; using i128 = __int128_t; using u128 = __uint128_t; i128 stoi128(const string &s) { i128 res = 0; if (s.front() == '-') { for (int i = 1; i < (int)s.size(); i++) res = 10 * res + s[i] - '0'; res = -res; } else { for (auto &&c : s) res = 10 * res + c - '0'; } return res; } string i128tos(i128 x) { if (x == 0) return "0"; string sign = "", res = ""; if (x < 0) x = -x, sign = "-"; while (x > 0) { res += '0' + x % 10; x /= 10; } reverse(res.begin(), res.end()); return sign + res; } istream &operator>>(istream &is, i128 &a) { string s; is >> s; a = stoi128(s); return is; } ostream &operator<<(ostream &os, const i128 &a) { os << i128tos(a); return os; } #define cauto const auto #define overload4(_1,_2,_3,_4,name,...) name #define repi1(i,n) for (int i = 0, nnnnn = int(n); i < nnnnn; i++) #define repi2(i,l,r) for (int i = int(l), rrrrr = int(r); i < rrrrr; i++) #define repi(...) overload4(__VA_ARGS__, repi3, repi2, repi1)(__VA_ARGS__) #define fe(...) for (auto __VA_ARGS__) #define fec(...) for (cauto &__VA_ARGS__) template constexpr bool is_integral_ext = is_integral_v || is_same_v || is_same_v; template constexpr bool is_signed_ext = is_signed_v || is_same_v; template constexpr bool is_unsigned_ext = is_unsigned_v || is_same_v; template inline bool chmin(T &a, U b) { return a > b ? a = b, true : false; } template && is_integral_ext>> inline constexpr T divfloor(U a, V b) { return T(a) / T(b) - (T(a) % T(b) && (T(a) ^ T(b)) < 0); } template && is_integral_ext>> inline constexpr T divround(U a, V b) { return divfloor(2 * T(a) + T(b), 2 * T(b)); } template && is_integral_ext>> inline constexpr T safemod(U a, V b) { return T(a) - T(b) * divfloor(a, b); } template constexpr T ipow(U a, V b) { assert(b >= 0); if (b == 0) return 1; if (a == 0 || a == 1) return a; if (a < 0 && a == -1) return b & 1 ? -1 : 1; T res = 1, tmp = a; while (true) { if (b & 1) res *= tmp; b >>= 1; if (b == 0) break; tmp *= tmp; } return res; } template T mul_limited(A a, B b, M m) { assert(a >= 0 && b >= 0 && m >= 0); if (b == 0) return 0; return T(a) > T(m) / T(b) ? T(m) : T(a) * T(b); } template T mul_limited(A a, B b) { return mul_limited(a, b, INF); } template T pow_limited(A a, B b, M m) { assert(a >= 0 && b >= 0 && m >= 0); if (a <= 1 || b == 0) return min(ipow(a, b), T(m)); T res = 1, tmp = a; while (true) { if (b & 1) { if (res > T(m) / tmp) return m; res *= tmp; } b >>= 1; if (b == 0) break; if (tmp > T(m) / tmp) return m; tmp *= tmp; } return res; } template T pow_limited(A a, B b) { return pow_limited(a, b, INF); } template constexpr T iroot(A a, K k) { assert(a >= 0 && k >= 1); if (a <= 1 || k == 1) return a; if (k == 2) { if constexpr (sizeof(T) > sizeof(ull)) { if ((u128)a < ((u128)1 << 120)) return sqrtl(a); } else return sqrtl(a); } auto isok = [&](T x) -> bool { if (x == 0) return true; T res = 1, k2 = k; while (true) { if (k2 & 1) { if (res > T(a) / x) return false; res *= x; } k2 >>= 1; if (k2 == 0) break; if (x > T(a) / x) return false; x *= x; } return res <= T(a); }; T x = pow(a, 1.0 / k); bool up = true; while (!isok(x)) up = false, x--; if (up) { while (x < numeric_limits::max() && isok(x + 1)) x++; } return x; } template vc base_repr(U val, V base) { assert(val >= 0); assert(base >= 2); if (val == 0) return {0}; vc a; while (val > 0) { a.emplace_back(val % base); val /= base; } reverse(a.begin(), a.end()); return a; } template vc base_repr(U val, V base, int n) { assert(val >= 0); assert(base >= 2); assert(n >= 0); vc a(n); repi(i, n) { a[i] = val % base; val /= base; } reverse(a.begin(), a.end()); return a; } template string base_repr_str(U val, int base, int n) { assert(val >= 0); assert(2 <= base && base <= 36); assert(n >= 0); auto a = base_repr(val, base, n); string s = ""; for (cauto &ai : a) s += (ai < 10 ? '0' + ai : (use_upper ? 'A' : 'a') + (ai - 10)); return s; } #define ALL(a) (a).begin(), (a).end() template inline T SZ(const V &x) { return x.size(); } #define eb emplace_back #define LMD(x,fx) ([&](auto x) { return fx; }) template auto gen_vec(int n, const F &f) { vc res(n); repi(i, n) res[i] = f(i); return res; } template auto dvec(const V (&sz)[d], const T &init) { if constexpr (i < d) return vc(sz[i], dvec(sz, init)); else return init; } template T ctol(const char &c, const string &s) { repi(i, SZ(s)) if (s[i] == c) return i; return -1; } template vc stov(const string &s, const string &t) { return gen_vec(SZ(s), [&](int i) -> T { return ctol(s[i], t); }); } template string vtos(const vc &v, const string &t) { string res = ""; fe(vi : v) res += t[vi]; return res; } template vc concat(const vc &v) { return v; } template vc concat(vc v, const vc &...vs) { (v.insert(v.end(), ALL(vs)), ...); return v; } template T SUM(const V &v) { T s{}; fec(vi : v) s += vi; return s; } template auto MAX(const V &v) { return *max_element(ALL(v)); } template vc permuted(const vc &a, const vc &p) { const int n = p.size(); vc res(n); repi(i, n) { assert(0 <= p[i] && p[i] < U(a.size())); res[i] = a[p[i]]; } return res; } template vc permuted(const vc &p, const vc &q, const vc &...rs) { return permuted(permuted(p, q), rs...); } template V reversed(const V &v) { return V(v.rbegin(), v.rend()); } template void unique(V &v) { v.erase(std::unique(ALL(v)), v.end()); } template void sortunique(V &v) { sort(ALL(v)); unique(v); } template void rotate(V &v, U k) { const U n = v.size(); k = (k % n + n) % n; std::rotate(v.begin(), v.begin() + k, v.end()); } template vvc top(const vvc &a) { if (a.empty()) return {}; const int n = a.size(), m = a[0].size(); vvc b(m, vc(n)); repi(i, n) { assert(SZ(a[i]) == m); repi(j, m) b[j][i] = a[i][j]; } return b; } vstr top(const vstr &a) { vvc a_(a.size()); repi(i, SZ(a)) a_[i] = {ALL(a[i])}; vvc b_ = top(a_); vstr b(b_.size()); repi(i, SZ(b)) b[i] = {ALL(b_[i])}; return b; } template struct has_e0 : false_type {}; template struct has_e0> : true_type {}; template inline constexpr bool has_e0_v = has_e0::value; template struct MonoidAdd { using S = T; static constexpr S op(S a, S b) { return a + b; } static constexpr S e() { if constexpr (has_e0_v) return S::e0(); else return {}; } }; template struct MonoidMin { using S = T; static constexpr S op(S a, S b) { return min(a, b); } static constexpr S e() { return infty; } }; template struct MonoidMax { using S = T; static constexpr S op(S a, S b) { return max(a, b); } static constexpr S e() { return -infty; } }; template vc cuml(const vc &v, int left_index = 0) { const int n = v.size(); vc res(n + 1); res[0] = M::e(); repi(i, n) res[i + 1] = M::op(res[i], v[i]); res.erase(res.begin(), res.begin() + left_index); return res; } template vc cumr(const vc &v, int right_index = 0) { return reversed(cuml(reversed(v), right_index)); } const vpll DRULgrid = {{1, 0}, {0, 1}, {-1, 0}, {0, -1}}; const vpll DRULplane = {{0, -1}, {1, 0}, {0, 1}, {-1, 0}}; template struct is_random_access_iterator { static constexpr bool value = is_same_v< typename iterator_traits::iterator_category, random_access_iterator_tag >; }; template constexpr bool is_random_access_iterator_v = is_random_access_iterator::value; template inline T LB(const V &v, const Value &val, Comp comp = {}, Proj proj = {}) { return ranges::lower_bound(v, val, comp, proj) - v.begin(); } template inline T UB(const V &v, const Value &val, Comp comp = {}, Proj proj = {}) { return ranges::upper_bound(v, val, comp, proj) - v.begin(); } #define DEFAULT_COMP ranges::less template inline auto lt_cnt(const V &v, const Value &val, Comp comp = {}, Proj proj = {}) -> enable_if_t, T> { return LB(v, val, comp, proj); } template inline auto lt_max(const V &v, const Value &val) -> enable_if_t, typename V::const_iterator> { auto it = v.lower_bound(val); return it == v.begin() ? v.end() : prev(it); } template inline auto leq_max(const V &v, const Value &val) -> enable_if_t, typename V::const_iterator> { auto it = v.upper_bound(val); return it == v.begin() ? v.end() : prev(it); } template inline auto gt_min(const V &v, const Value &val) -> enable_if_t, typename V::const_iterator> { return v.upper_bound(val); } template inline auto geq_min(const V &v, const Value &val) -> enable_if_t, typename V::const_iterator> { return v.lower_bound(val); } template inline constexpr ull MASK(T k) { return (1ULL << k) - 1ULL; } inline constexpr ll bit_width(ll x) { return std::bit_width((ull)x); } inline constexpr ll bit_floor(ll x) { return std::bit_floor((ull)x); } inline constexpr ll bit_ceil(ll x) { return std::bit_ceil((ull)x); } inline constexpr ll countr_zero(ll x) { assert(x != 0); return std::countr_zero((ull)x); } inline constexpr ll popcount(ll x) { return std::popcount((ull)x); } inline constexpr bool has_single_bit(ll x) { return std::has_single_bit((ull)x); } #define dump(...) #define oj(...) __VA_ARGS__ template vc content(queue que) { vc res; while (!que.empty()) { res.eb(que.front()); que.pop(); } return res; } template vc content(priority_queue pque) { vc res; while (!pque.empty()) { res.eb(pque.top()); pque.pop(); } return res; } template auto content(const T &obj) { return obj.content(); } namespace fastio { static constexpr uint32_t SIZ = 1 << 17; char ibuf[SIZ]; char obuf[SIZ]; char out[100]; uint32_t pil = 0, pir = 0, por = 0; struct Pre { char num[10000][4]; constexpr Pre() : num() { for (int i = 0; i < 10000; i++) { int n = i; for (int j = 3; j >= 0; j--) { num[i][j] = n % 10 | '0'; n /= 10; } } } } constexpr pre; inline void load() { memcpy(ibuf, ibuf + pil, pir - pil); pir = pir - pil + fread(ibuf + pir - pil, 1, SIZ - pir + pil, stdin); pil = 0; if (pir < SIZ) ibuf[pir++] = '\n'; } inline void flush() { fwrite(obuf, 1, por, stdout); por = 0; } void rd1(char &c) { do { if (pil + 1 > pir) load(); c = ibuf[pil++]; } while (isspace(c)); } void rd1(string &x) { x.clear(); char c; do { if (pil + 1 > pir) load(); c = ibuf[pil++]; } while (isspace(c)); do { x += c; if (pil == pir) load(); c = ibuf[pil++]; } while (!isspace(c)); } template void rd1_real(T &x) { string s; rd1(s); x = stod(s); } template void rd1_integer(T &x) { if (pil + 100 > pir) load(); char c; do c = ibuf[pil++]; while (c < '-'); bool minus = 0; if constexpr (is_signed::value || is_same_v) { if (c == '-') { minus = 1, c = ibuf[pil++]; } } x = 0; while ('0' <= c) { x = x * 10 + (c & 15), c = ibuf[pil++]; } pil--; if constexpr (is_signed::value || is_same_v) { if (minus) x = -x; } } void rd1(int &x) { rd1_integer(x); } void rd1(ll &x) { rd1_integer(x); } void rd1(i128 &x) { rd1_integer(x); } void rd1(uint &x) { rd1_integer(x); } void rd1(ull &x) { rd1_integer(x); } void rd1(u128 &x) { rd1_integer(x); } void rd1(double &x) { rd1_real(x); } void rd1(long double &x) { rd1_real(x); } template void rd1(pair &p) { return rd1(p.first), rd1(p.second); } template void rd1_tuple(T &t) { if constexpr (N < std::tuple_size::value) { auto &x = std::get(t); rd1(x); rd1_tuple(t); } } template void rd1(tuple &tpl) { rd1_tuple(tpl); } template void rd1(array &x) { for (auto &d: x) rd1(d); } template void rd1(vc &x) { for (auto &d: x) rd1(d); } void read() {} template void read(H &h, T &... t) { rd1(h), read(t...); } void wt1(const char c) { if (por == SIZ) flush(); obuf[por++] = c; } void wt1(const string s) { for (char c: s) wt1(c); } void wt1(const char *s) { size_t len = strlen(s); for (size_t i = 0; i < len; i++) wt1(s[i]); } template void wt1_integer(T x) { if (por > SIZ - 100) flush(); if (x < 0) { obuf[por++] = '-', x = -x; } int outi; for (outi = 96; x >= 10000; outi -= 4) { memcpy(out + outi, pre.num[x % 10000], 4); x /= 10000; } if (x >= 1000) { memcpy(obuf + por, pre.num[x], 4); por += 4; } else if (x >= 100) { memcpy(obuf + por, pre.num[x] + 1, 3); por += 3; } else if (x >= 10) { int q = (x * 103) >> 10; obuf[por] = q | '0'; obuf[por + 1] = (x - q * 10) | '0'; por += 2; } else obuf[por++] = x | '0'; memcpy(obuf + por, out + outi + 4, 96 - outi); por += 96 - outi; } template void wt1_real(T x) { ostringstream oss; oss << fixed << setprecision(15) << double(x); string s = oss.str(); wt1(s); } void wt1(int x) { wt1_integer(x); } template , int> = 0> void wt1(T x) { wt1_integer(x); } void wt1(i128 x) { wt1_integer(x); } void wt1(u128 x) { wt1_integer(x); } void wt1(double x) { wt1_real(x); } void wt1(long double x) { wt1_real(x); } template void wt1(const pair &val) { wt1(val.first); wt1(' '); wt1(val.second); } template void wt1_tuple(const T &t) { if constexpr (N < std::tuple_size::value) { if constexpr (N > 0) { wt1(' '); } const auto x = std::get(t); wt1(x); wt1_tuple(t); } } template void wt1(const tuple &tpl) { wt1_tuple(tpl); } template void wt1(const array &val) { auto n = val.size(); for (size_t i = 0; i < n; i++) { if (i) wt1(' '); wt1(val[i]); } } template void wt1(const vector &val) { auto n = val.size(); for (size_t i = 0; i < n; i++) { if (i) wt1(' '); wt1(val[i]); } } void write() {} template void write(Head &&head, Tail &&... tail) { wt1(head); write(std::forward(tail)...); } void print() { wt1('\n'); } template void print(Head &&head, Tail &&... tail) { wt1(head); if (sizeof...(Tail)) wt1(' '); print(std::forward(tail)...); } } struct Dummy { Dummy() { atexit(fastio::flush); } } dummy; namespace internal { template void READnodump(Ts &...a) { fastio::read(a...); } template void READVECnodump(int n, vc &v) { v.resize(n); READnodump(v); } template void READVECnodump(int n, vc &v, vc &...vs) { READVECnodump(n, v), READVECnodump(n, vs...); } template void READVEC2nodump(int n, int m, vvc &v) { v.assign(n, vc(m)); READnodump(v); } template void READVEC2nodump(int n, int m, vvc &v, vvc &...vs) { READVEC2nodump(n, m, v), READVEC2nodump(n, m, vs...); } template void READJAGnodump(int n, vvc &v) { v.resize(n); repi(i, n) { int k; READnodump(k); READVECnodump(k, v[i]); } } template void READJAGnodump(int n, vvc &v, vvc &...vs) { READJAGnodump(n, v), READJAGnodump(n, vs...); } }; #define READ(...) internal::READnodump(__VA_ARGS__); dump(__VA_ARGS__) #define IN(T,...) T __VA_ARGS__; READ(__VA_ARGS__) #define LL(...) IN(ll, __VA_ARGS__) #define READVEC(...) internal::READVECnodump(__VA_ARGS__); dump(__VA_ARGS__) #define READVEC2(...) internal::READVEC2nodump(__VA_ARGS__); dump(__VA_ARGS__) #define VEC(T,n,...) vc __VA_ARGS__; READVEC(n, __VA_ARGS__) #define READJAG(...) internal::READJAGnodump(__VA_ARGS__); dump(__VA_ARGS__) #define PRINT fastio::print template pair operator+=(pair &a, const P &b) { a.first += b.first; a.second += b.second; return a; } template pair operator+(pair &a, const P &b) { return a += b; } template array operator+=(array &a, const A &b) { for (size_t i = 0; i < n; i++) a[i] += b[i]; return a; } template array operator+(array &a, const A &b) { return a += b; } namespace internal { template auto tuple_add_impl(A &a, const B &b, const index_sequence) { ((get(a) += get(b)), ...); return a; } }; template tuple operator+=(tuple &a, const Tp &b) { return internal::tuple_add_impl(a, b, make_index_sequence>>{}); } template tuple operator+(tuple &a, const Tp &b) { return a += b; } template void offset(vvc &v, const Add &add) { for (auto &vi : v) for (auto &vij : vi) vij += add; } template pair, vc> unzip(const vc> &vt) { const size_t n = vt.size(); pair, vc> tv; tv.first.resize(n), tv.second.resize(n); for (size_t i = 0; i < n; i++) tie(tv.first[i], tv.second[i]) = vt[i]; return tv; } template vc> zip(const pair, vc> &tv) { const size_t n = tv.first.size(); assert(n == tv.second.size()); vc> vt(n); for (size_t i = 0; i < n; i++) vt[i] = make_pair(tv.first[i], tv.second[i]); return vt; } namespace internal { template auto vt_to_tv_impl(V &tv, const Tp &t, index_sequence, size_t index) { ((get(tv)[index] = get(t)), ...); } template auto tv_to_vt_impl(const Tp &tv, index_sequence, size_t index) { return make_tuple(get(tv)[index]...); } }; template auto unzip(const vc> &vt) { const size_t n = vt.size(); tuple...> tv; apply([&](auto &...v) { ((v.resize(n)), ...); }, tv); for (size_t i = 0; i < n; i++) internal::vt_to_tv_impl(tv, vt[i], make_index_sequence>{}, i); return tv; } template auto zip(const tuple...> &tv) { size_t n = get<0>(tv).size(); apply([&](auto &...v) { ((assert(v.size() == n)), ...); }, tv); vc> vt(n); for (size_t i = 0; i < n; i++) vt[i] = internal::tv_to_vt_impl(tv, index_sequence_for{}, i); return vt; } mt19937_64 mt; template T randint(U1 l, U2 r) { assert(T(l) <= T(r)); return T(l) + mt() % (T(r) - T(l) + 1); } template struct larger_int { using type = T; }; #define LARGER_INT(T,U) template <> struct larger_int { using type = U; }; LARGER_INT(signed char, short) LARGER_INT(short, int) LARGER_INT(int, long long) LARGER_INT(long, __int128_t) LARGER_INT(long long, __int128_t) LARGER_INT(unsigned char, unsigned short) LARGER_INT(unsigned short, unsigned int) LARGER_INT(unsigned int, unsigned long long) LARGER_INT(unsigned long, __uint128_t) LARGER_INT(unsigned long long, __uint128_t) #undef LARGER_INT template using larger_int_t = typename larger_int::type; namespace internal { template constexpr ll powmod_constexpr(ll x, ll n, T m) { if (m == 1) return 0; using U = make_unsigned_t; using L = larger_int_t; U r = 1, y = safemod(x, m); while (n) { if (n & 1) r = L(r) * y % m; y = L(y) * y % m; n >>= 1; } return r; } template constexpr bool isprime_constexpr(T n) { if constexpr (sizeof(T) > 4) { if (n <= INT_MAX) return isprime_constexpr(n); } if (n <= 1) return false; if (n == 2 || n == 7 || n == 61) return true; if (n % 2 == 0) return false; ll d = n - 1; while (d % 2 == 0) d /= 2; using U = make_unsigned_t; using L = larger_int_t; auto miller_rabin = [&](const auto &bases) constexpr { for (ll a : bases) { ll t = d, y = powmod_constexpr(a, t, n); while (t != n - 1 && y != 1 && y != n - 1) { y = L(y) * y % n; t <<= 1; } if (y != n - 1 && t % 2 == 0) return false; } return true; }; if constexpr(sizeof(T) <= 4) { constexpr ll bases[3] = {2, 7, 61}; return miller_rabin(bases); } else { constexpr ll bases[7] = {2, 325, 9375, 28178, 450775, 9780504, 1795265022}; return miller_rabin(bases); } } template constexpr bool isprime = isprime_constexpr(n); }; namespace internal { template struct policy_static { using mod_type = decltype(M); using value_type = make_unsigned_t; using calc_type = larger_int_t; static constexpr bool is_prime = isprime_constexpr(M); static constexpr mod_type mod() { return M; } static constexpr value_type umod() { return M; } static constexpr value_type init(value_type v) { return v; } static constexpr mod_type val(value_type v) { return v; } static constexpr value_type mul(value_type a, value_type b) { return (value_type)((calc_type(a) * b) % M); } }; }; namespace internal { struct barrett32 { uint m; ull im; explicit barrett32(uint m) : m(m), im((ull)(-1) / m + 1) {} uint umod() const { return m; } uint mul(uint a, uint b) const { ull z = a; z *= b; ull x = ull((u128(z) * im) >> 64); ull y = x * m; return uint(z - y + (z < y ? m : 0)); } }; template struct policy_barrett32 { using value_type = uint; using calc_type = ull; using mod_type = int; static constexpr bool is_prime = false; static inline barrett32 reducer{998244353}; static void set_mod(mod_type m) { reducer = barrett32(m); } static mod_type mod() { return reducer.umod(); } static value_type umod() { return reducer.umod(); } static value_type init(value_type v) { return v; } static mod_type val(value_type v) { return v; } static value_type mul(value_type a, value_type b) { return reducer.mul(a, b); } }; }; namespace internal { inline constexpr ull inv64(ull a) { ull x = a; while (a * x != 1) x *= 2 - a * x; return x; } struct montgomery64odd { ull m, im, sq; explicit montgomery64odd(ull m) : m(m), im(inv64(m)), sq(-u128(m) % m) {} ull umod() const { return m; } ull reduce(u128 x) const { auto t = (x + u128(m) * (-im * ull(x))) >> 64; if (t >= m) t -= m; return (ull)t; } ull inv_reduce(i128 v) const { return reduce(u128(v % m + m) * sq); } }; struct montgomery64 { ull m, mx, imx, d, q; uint b; explicit montgomery64(ull m) : m(m) { b = countr_zero(m), mx = m >> b; imx = inv64(mx); d = powmod_constexpr((mx + 1) / 2, b, mx); u128 sq = -u128(mx) % mx; q = (1 + (((sq - 1) * d) << b)) % m; } ull umod() const { return m; } ull reduce(u128 x) const { ull p = x & MASK(b); x = (x >> b) + p * d; ull y = p << (64 - b); auto t = (x + u128(mx) * (imx * (y - ull(x)))) >> (64 - b); if (t >= m) { t -= m; if (t >= m) t -= m; } return (ull)t; } ull inv_reduce(i128 v) const { return reduce(u128(v % m + m) * q); } }; template struct policy_montgomery64_odd { using value_type = ull; using calc_type = u128; using mod_type = ll; static constexpr bool is_prime = false; static inline montgomery64odd reducer{(1LL << 61) - 1}; static void set_mod(mod_type m) { reducer = montgomery64odd(m); } static mod_type mod() { return reducer.umod(); } static value_type umod() { return reducer.umod(); } static value_type init(value_type v) { return reducer.inv_reduce(v); } static mod_type val(value_type v) { return reducer.reduce(v); } static value_type mul(value_type a, value_type b) { return reducer.reduce((calc_type)a * b); } }; template struct policy_montgomery64 { using value_type = ull; using calc_type = u128; using mod_type = ll; static constexpr bool is_prime = false; static inline montgomery64 reducer{(1LL << 61) - 1}; static void set_mod(mod_type m) { reducer = montgomery64(m); } static mod_type mod() { return reducer.umod(); } static value_type umod() { return reducer.umod(); } static value_type init(value_type v) { return reducer.inv_reduce(v); } static mod_type val(value_type v) { return reducer.reduce(v); } static value_type mul(value_type a, value_type b) { return reducer.reduce((calc_type)a * b); } }; }; template constexpr tuple extgcd(T a, T b) { if (a == 0 && b == 0) return {0, 0, 0}; T x1 = 1, y1 = 0, z1 = a; T x2 = 0, y2 = 1, z2 = b; while (z2 != 0) { T q = z1 / z2; tie(x1, x2) = make_pair(x2, x1 - q * x2); tie(y1, y2) = make_pair(y2, y1 - q * y2); tie(z1, z2) = make_pair(z2, z1 - q * z2); } if (z1 < 0) x1 = -x1, y1 = -y1, z1 = -z1; return {z1, x1, y1}; } namespace internal { template struct modint_impl { using V = typename Policy::value_type; using M = typename Policy::mod_type; using mint = modint_impl; private: V _v; public: static constexpr M mod() { return Policy::mod(); } template static auto set_mod(M m) -> decltype(T::set_mod(m)) { return T::set_mod(m); } static mint raw(V v) { mint x; x._v = v; return x; } modint_impl() : _v(0) {} template >> modint_impl(T v) { V rem; if constexpr (is_signed_ext) { using S = make_signed_t; S x = v % S(Policy::umod()); if (x < 0) x += Policy::umod(); rem = x; } else rem = V(v % Policy::umod()); _v = Policy::init(rem); }; M val() const { return Policy::val(_v); } mint &operator+=(const mint &rhs) { _v += rhs._v; if (_v >= Policy::umod()) _v -= Policy::umod(); return *this; } mint &operator-=(const mint &rhs) { _v -= rhs._v; if (_v >= Policy::umod()) _v += Policy::umod(); return *this; } mint &operator*=(const mint &rhs) { _v = Policy::mul(_v, rhs._v); return *this; } mint &operator/=(const mint &rhs) { return *this *= rhs.inv(); } mint &operator++() { _v++; if (_v == Policy::umod()) _v = 0; return *this; } mint &operator--() { if (_v == 0) _v = Policy::umod(); _v--; return *this; } mint operator++(int) { mint res = *this; ++(*this); return res; } mint operator--(int) { mint res = *this; --(*this); return res; } mint operator+() const { return *this; } mint operator-() const { return mint() - *this; } template mint pow(T n) const { assert(n >= 0); mint x = *this, r = 1; while (n) { if (n & 1) r *= x; x *= x; n >>= 1; } return r; } mint inv() const { if constexpr (Policy::is_prime) { return pow(mod() - 2); } else { auto [g, x, y] = extgcd(val(), mod()); assert(g == 1); return mint(x); } } friend mint operator+(const mint &lhs, const mint &rhs) { return mint(lhs) += rhs; } friend mint operator-(const mint &lhs, const mint &rhs) { return mint(lhs) -= rhs; } friend mint operator*(const mint &lhs, const mint &rhs) { return mint(lhs) *= rhs; } friend mint operator/(const mint &lhs, const mint &rhs) { return mint(lhs) /= rhs; } friend bool operator==(const mint &lhs, const mint &rhs) { return lhs._v == rhs._v; } friend bool operator!=(const mint &lhs, const mint &rhs) { return lhs._v != rhs._v; } friend void rd1(mint &x) { long long a; fastio::rd1(a); x = a; } friend void wt1(const mint &x) { fastio::wt1(x.val()); } }; }; template using static_modint32 = internal::modint_impl>; template using dynamic_modint32 = internal::modint_impl>; template using static_modint64 = internal::modint_impl>; template using dynamic_modint64_odd = internal::modint_impl>; template using dynamic_modint64 = internal::modint_impl>; using modint998244353 = static_modint32<998244353>; template struct is_modint : std::false_type { }; template struct is_modint> : std::true_type { }; template inline constexpr bool is_modint_v = is_modint::value; template struct is_static_modint : false_type {}; template struct is_static_modint> : true_type {}; template struct is_static_modint> : true_type {}; template inline constexpr bool is_static_modint_v = is_static_modint::value; template struct is_dynamic_modint : false_type {}; template struct is_dynamic_modint> : true_type {}; template struct is_dynamic_modint> : true_type {}; template struct is_dynamic_modint> : true_type {}; template inline constexpr bool is_dynamic_modint_v = is_dynamic_modint::value; template struct has_mod : std::false_type { }; template struct has_mod> : std::true_type { }; template struct PowerTable { private: decltype(mint::mod()) mod; mint base; vc pw; public: PowerTable() {} PowerTable(const mint &base) : mod(mint::mod()), base(base), pw(1, 1) {} void reserve(int n) { if (mod != mint::mod()) { mod = mint::mod(); pw = {1}; } int i = pw.size(); if (n < i) return; pw.resize(n + 1); for (; i <= n; i++) pw[i] = pw[i - 1] * base; } mint pow(int n) { reserve(n); return pw[n]; } }; template struct Binomial { private: inline static decltype(T::mod()) mod; public: inline static vc fac_, finv_, inv_; static void reserve(int n) { if constexpr (is_dynamic_modint_v) { if (mod != T::mod()) { mod = T::mod(); fac_ = {1, 1}, finv_ = {1, 1}, inv_ = {0, 1}; } } else { if (fac_.empty()) fac_ = {1, 1}, finv_ = {1, 1}, inv_ = {0, 1}; } if (n < SZ(fac_)) return; chmin(n, T::mod() - 1); int si = fac_.size(); fac_.resize(n + 1), finv_.resize(n + 1), inv_.resize(n + 1); repi(i, si, n + 1) { fac_[i] = fac_[i - 1] * T::raw(i); inv_[i] = -inv_[T::mod() % i] * T::raw(T::mod() / i); finv_[i] = finv_[i - 1] * inv_[i]; } } static T inv(int n) { assert(n != 0); reserve(n); return inv_[n]; } static T C(int n, int k) { if (n < k) return 0; if (n < 0 || k < 0) return 0; reserve(n); return fac_[n] * finv_[k] * finv_[n - k]; } }; template > pair svp2d(const pair &a, const pair &b) { assert((a != pair{0, 0} && b != pair{0, 0})); auto [a1, a2] = a; auto [b1, b2] = b; if ((U)a1 * a1 + (U)a2 * a2 < (U)b1 * b1 + (U)b2 * b2) swap(a1, b1), swap(a2, b2); while ((U)a1 * a1 + (U)a2 * a2 > (U)b1 * b1 + (U)b2 * b2) { swap(a1, b1), swap(a2, b2); T k = divround((U)a1 * b1 + (U)a2 * b2, (U)a1 * a1 + (U)a2 * a2); b1 -= k * a1, b2 -= k * a2; } return {a1, a2}; } template pair mint_to_rat(const mint &x) { auto [p, q] = svp2d({x.val(), 1}, {mint::mod(), 0}); if (q < 0) p = -p, q = -q; return {p, q}; } namespace cpp_dump { struct mint_to_rat_fn { template constexpr auto operator()(const T &x) const -> decltype(mint_to_rat(x)) { return mint_to_rat(x); } }; struct rat_closure : std::ranges::range_adaptor_closure { template constexpr auto operator()(T &&t) const { if constexpr (!std::ranges::range && std::invocable(t))>) { return mint_to_rat_fn{}(std::forward(t)); } else if constexpr (std::ranges::range) { using Ref = std::ranges::range_reference_t; if constexpr (std::invocable(std::declval()))>) { return std::forward(t) | std::views::transform(mint_to_rat_fn{}); } else if constexpr (std::ranges::range) { return std::forward(t) | std::views::transform([this](auto &&inner) { return (*this)(std::forward(inner)); }); } else { static_assert(false); } } else { static_assert(false); } } }; template requires(!std::ranges::range && std::invocable) constexpr auto operator|(T &&t, const rat_closure &c) { return c(std::forward(t)); } } using mint = modint998244353; using bi = Binomial; void init() { oj(mt.seed(random_device()())); } struct use_std_nth_element { template void operator()(RandomIt first, RandomIt nth, RandomIt last, Compare comp) const { std::nth_element(first, nth, last, comp); } }; struct use_median_of_medians { private: template static void select_impl(RandomIt first, RandomIt nth, RandomIt last, Compare comp) { using difference_type = typename std::iterator_traits::difference_type; using value_type = typename std::iterator_traits::value_type; constexpr difference_type small_limit = 32; while (last - first > small_limit) { RandomIt medians_end = first; for (RandomIt group_first = first; group_first < last; group_first += 5) { const difference_type remaining = last - group_first; RandomIt group_last = group_first + std::min(5, remaining); std::sort(group_first, group_last, comp); RandomIt median = group_first + (group_last - group_first) / 2; std::iter_swap(medians_end, median); ++medians_end; } RandomIt pivot_pos = first + (medians_end - first) / 2; select_impl(first, pivot_pos, medians_end, comp); const value_type pivot = *pivot_pos; RandomIt equal_first = std::partition( first, last, [&](const value_type& x) { return comp(x, pivot); }); RandomIt equal_last = std::partition( equal_first, last, [&](const value_type& x) { return !comp(pivot, x); }); if (nth < equal_first) { last = equal_first; } else if (nth >= equal_last) { first = equal_last; } else { return; } } std::sort(first, last, comp); } public: template void operator()(RandomIt first, RandomIt nth, RandomIt last, Compare comp) const { assert(first <= nth && nth < last); select_impl(first, nth, last, comp); } }; namespace sorted_matrix_selection_detail { using rank_type = std::uint64_t; enum class answer_kind : unsigned char { upper, lower, middle }; struct answer_location { answer_kind kind; rank_type middle_rank = 0; }; template class selector { public: using value_type = std::decay_t< std::invoke_result_t>; selector(std::size_t n, Accessor accessor, Compare compare, LocalSelector local_selector) : original_n_(n), accessor_(std::move(accessor)), compare_(std::move(compare)), local_selector_(std::move(local_selector)) {} value_type run(rank_type k) { if (original_n_ == 0) { throw std::invalid_argument( "sorted_matrix_select: n must be positive"); } const rank_type rank_n = static_cast(original_n_); if (static_cast(rank_n) != original_n_ || rank_n > std::numeric_limits::max() / rank_n) { throw std::overflow_error( "sorted_matrix_select: n*n does not fit in uint64_t"); } const rank_type total = rank_n * rank_n; if (k >= total) { throw std::out_of_range( "sorted_matrix_select: k is outside [0, n*n)"); } std::vector positions(original_n_); std::iota(positions.begin(), positions.end(), std::size_t{0}); return biselect(positions, k + 1, k + 1).first; } private: value_type at(const std::vector& positions, std::size_t i, std::size_t j) { return std::invoke(accessor_, positions[i], original_n_ - 1 - positions[j]); } bool less(const value_type& x, const value_type& y) { return std::invoke(compare_, x, y); } static rank_type ceil_div4(rank_type x) { return x / 4 + static_cast(x % 4 != 0); } static rank_type ceil_div4_sum(rank_type x, rank_type y) { return x / 4 + y / 4 + static_cast((x % 4 + y % 4 + 3) / 4); } std::pair biselect(const std::vector& positions, rank_type k1, rank_type k2) { const std::size_t n = positions.size(); const rank_type total = static_cast(n) * n; assert(n > 0); assert(1 <= k2 && k2 <= k1 && k1 <= total); if (n <= 2) { std::vector values; values.reserve(n * n); for (std::size_t i = 0; i < n; ++i) { for (std::size_t j = 0; j < n; ++j) { values.push_back(at(positions, i, j)); } } std::sort(values.begin(), values.end(), std::ref(compare_)); return {values[static_cast(k1 - 1)], values[static_cast(k2 - 1)]}; } const std::size_t sub_n = (n + 2) / 2; std::vector sub_positions(sub_n); for (std::size_t i = 0; i < sub_n; ++i) { sub_positions[i] = positions[std::min(2 * i, n - 1)]; } rank_type sub_k1; if ((n & 1U) == 0) { sub_k1 = static_cast(n) + 1 + ceil_div4(k1); } else { sub_k1 = ceil_div4_sum( k1, 2 * static_cast(n) + 1); } const rank_type sub_k2 = ceil_div4(k2); const rank_type sub_total = static_cast(sub_n) * sub_n; assert(1 <= sub_k2 && sub_k2 <= sub_k1 && sub_k1 <= sub_total); auto [upper, lower] = biselect(sub_positions, sub_k1, sub_k2); assert(!less(upper, lower)); rank_type rank_less_upper = 0; rank_type rank_greater_lower = 0; std::size_t first_less_upper = 0; std::size_t first_not_greater_lower = 0; for (std::size_t i = 0; i < n; ++i) { while (first_less_upper < n) { value_type x = at(positions, i, first_less_upper); if (less(x, upper)) break; ++first_less_upper; } rank_less_upper += n - first_less_upper; while (first_not_greater_lower < n) { value_type x = at(positions, i, first_not_greater_lower); if (!less(lower, x)) break; ++first_not_greater_lower; } rank_greater_lower += first_not_greater_lower; } const auto locate = [&](rank_type k) -> answer_location { if (rank_less_upper <= k - 1) { return {answer_kind::upper, 0}; } const rank_type count_not_greater_lower = total - rank_greater_lower; if (k <= count_not_greater_lower) { return {answer_kind::lower, 0}; } return {answer_kind::middle, k - count_not_greater_lower}; }; const answer_location where1 = locate(k1); const answer_location where2 = locate(k2); if (where1.kind != answer_kind::middle && where2.kind != answer_kind::middle) { return {where1.kind == answer_kind::upper ? upper : lower, where2.kind == answer_kind::upper ? upper : lower}; } assert(less(lower, upper)); assert(rank_less_upper + rank_greater_lower >= total); const rank_type middle_count = rank_less_upper - (total - rank_greater_lower); assert(middle_count <= static_cast( std::numeric_limits::max())); std::vector middle; middle.reserve(static_cast(middle_count)); first_less_upper = 0; first_not_greater_lower = 0; for (std::size_t i = 0; i < n; ++i) { while (first_less_upper < n) { value_type x = at(positions, i, first_less_upper); if (less(x, upper)) break; ++first_less_upper; } while (first_not_greater_lower < n) { value_type x = at(positions, i, first_not_greater_lower); if (!less(lower, x)) break; ++first_not_greater_lower; } for (std::size_t j = first_less_upper; j < first_not_greater_lower; ++j) { middle.push_back(at(positions, i, j)); } } assert(middle.size() == middle_count); const auto pick = [&](rank_type r) -> value_type { assert(1 <= r && r <= middle.size()); auto nth = middle.begin() + static_cast(r - 1); std::invoke(local_selector_, middle.begin(), nth, middle.end(), std::ref(compare_)); return *nth; }; value_type answer1 = where1.kind == answer_kind::upper ? upper : where1.kind == answer_kind::lower ? lower : pick(where1.middle_rank); value_type answer2 = where2.kind == answer_kind::upper ? upper : where2.kind == answer_kind::lower ? lower : pick(where2.middle_rank); return {std::move(answer1), std::move(answer2)}; } std::size_t original_n_; Accessor accessor_; Compare compare_; LocalSelector local_selector_; }; } template > auto sorted_matrix_select(std::size_t n, std::uint64_t k, Accessor accessor, Compare compare = {}) { using impl = sorted_matrix_selection_detail::selector< Accessor, Compare, use_std_nth_element>; return impl(n, std::move(accessor), std::move(compare), use_std_nth_element{}) .run(k); } template inline constexpr bool is_rational_ordered_v = is_integral_ext || is_floating_point_v; template struct Rational { using value_type = T; T num, den; private: void normalize_sign() { if constexpr (is_signed_ext || is_floating_point_v) if (den < T(0)) num = -num, den = -den; } static T gcd_abs(T a, T b) { if constexpr (is_signed_ext) { if (a < 0) a = -a; if (b < 0) b = -b; } while (b != T(0)) { T r = a % b; a = b, b = r; } return a; } public: Rational() : num(0), den(1) {} Rational(const T &num) : num(num), den(1) {} Rational(const T &num, const T &den) : num(num), den(den) { assert(den != T(0)); normalize_sign(); } pair reduced() const { if constexpr (is_integral_ext) { T g = gcd_abs(num, den); return g == T(0) ? pair{num, den} : pair{num / g, den / g}; } else return {num, den}; } Rational operator-() const { return {-num, den}; } Rational operator+() const { return *this; } Rational &operator+=(const Rational &rhs) { T rhs_num = rhs.num, rhs_den = rhs.den; num = num * rhs_den + rhs_num * den; den *= rhs_den; normalize_sign(); return *this; } Rational &operator-=(const Rational &rhs) { T rhs_num = rhs.num, rhs_den = rhs.den; num = num * rhs_den - rhs_num * den; den *= rhs_den; normalize_sign(); return *this; } Rational &operator*=(const Rational &rhs) { T rhs_num = rhs.num, rhs_den = rhs.den; num *= rhs_num; den *= rhs_den; normalize_sign(); return *this; } Rational &operator/=(const Rational &rhs) { assert(rhs.num != T(0)); T rhs_num = rhs.num, rhs_den = rhs.den; num *= rhs_den; den *= rhs_num; normalize_sign(); return *this; } friend Rational operator+(Rational lhs, const Rational &rhs) { return lhs += rhs; } friend Rational operator-(Rational lhs, const Rational &rhs) { return lhs -= rhs; } friend Rational operator*(Rational lhs, const Rational &rhs) { return lhs *= rhs; } friend Rational operator/(Rational lhs, const Rational &rhs) { return lhs /= rhs; } friend bool operator==(const Rational &lhs, const Rational &rhs) { using C = larger_int_t; return C(lhs.num) * C(rhs.den) == C(rhs.num) * C(lhs.den); } friend bool operator!=(const Rational &lhs, const Rational &rhs) { return !(lhs == rhs); } template , int> = 0> friend bool operator<(const Rational &lhs, const Rational &rhs) { using C = larger_int_t; return C(lhs.num) * C(rhs.den) < C(rhs.num) * C(lhs.den); } template , int> = 0> friend bool operator>(const Rational &lhs, const Rational &rhs) { return rhs < lhs; } template , int> = 0> friend bool operator<=(const Rational &lhs, const Rational &rhs) { return !(rhs < lhs); } template , int> = 0> friend bool operator>=(const Rational &lhs, const Rational &rhs) { return !(lhs < rhs); } friend ostream &operator<<(ostream &os, const Rational &x) { auto [num, den] = x.reduced(); return os << num << '/' << den; } friend void wt1(const Rational &x) { auto [num, den] = x.reduced(); using fastio::wt1; wt1(num), wt1('/'), wt1(den); } }; template struct is_rational : false_type {}; template struct is_rational> : true_type {}; template inline constexpr bool is_rational_v = is_rational::value; namespace std { template struct numeric_limits<::Rational> : numeric_limits { static constexpr bool is_specialized = numeric_limits::is_specialized; static ::Rational min() noexcept { return ::Rational(numeric_limits::min()); } static ::Rational lowest() noexcept { return ::Rational(numeric_limits::lowest()); } static ::Rational max() noexcept { return ::Rational(numeric_limits::max()); } static constexpr bool is_signed = numeric_limits::is_signed; static constexpr bool is_integer = false; static constexpr bool is_exact = numeric_limits::is_exact; }; } void main2() { LL(N); VEC(ll, N, A); sort(ALL(A)); auto ans = sorted_matrix_select(N, N * (N - 1) / 2, [&](ll i, ll j) { return Rational(A[i], A[j]); }); PRINT(ans.reduced()); } void test() { } template struct Main { Main() { cauto CERR = [](string val, string color) { string s = "\033[" + color + "m" + val + "\033[m"; }; CERR("\n[FAST_IO]\n\n", "32"); cout << fixed << setprecision(20); init(); CERR("\n[SINGLE_TESTCASE]\n\n", "36"); main2(); } }; Main main_dummy; int main() {}