#define INF 4'000'000'000'000'000'037LL #define EPS 1e-11 #include using namespace std; namespace { 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 vb = vc; using vpll = vc; using vstr = vc; #ifdef __SIZEOF_INT128__ using i128 = __int128_t; using u128 = __uint128_t; #endif #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 repi3(i, l, r, d) for (int i = int(l), rrrrr = int(r), ddddd = int(d); ddddd > 0 ? i < rrrrr : i > rrrrr; i += d) #define repi(...) overload4(__VA_ARGS__, repi3, repi2, repi1)(__VA_ARGS__) #define fe(...) for (auto __VA_ARGS__) #define fec(...) for (cauto &__VA_ARGS__) template inline bool chmin(T &a, U b) { return a > b ? a = b, true : false; } template inline constexpr T divfloor(U a, V b) { return T(a) / T(b) - (T(a) % T(b) && (T(a) ^ T(b)) < 0); } template 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 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; } #define ALL(a) (a).begin(), (a).end() template inline T SZ(const V &x) { return x.size(); } #define eb emplace_back 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 concat(vc v, const vc &...vs) { (v.insert(v.end(), ALL(vs)), ...); return v; } template auto SUM(const V &v) { typename V::value_type s{}; fec(vi : v) s += vi; return s; } template T SUM(const V &v) { T s{}; fec(vi : v) s += vi; return s; } 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()); } #if __cplusplus < 202002L #else #endif template void unique(V &v) { v.erase(std::unique(ALL(v)), v.end()); } 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; } template struct MonoidAdd { using S = T; static constexpr S op(S a, S b) { return a + b; } static constexpr S e() { return 0; } }; 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 cumlsum(const vc &v, int left_index = 0) { return cuml>(v, left_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; #if __cplusplus < 202002L struct identity { template constexpr T &&operator()(T &&t) const noexcept { return forward(t); } }; namespace internal { template inline T bound_helper(const V &v, Judge judge) { int l = -1, r = v.size(); while (r - l > 1) { int m = (l + r) / 2; if (judge(m)) l = m; else r = m; } return r; } }; template , class Proj = identity> inline T LB(const V &v, const Value &val, Comp comp = {}, Proj proj = {}) { return internal::bound_helper(v, [&](int i) -> bool { return comp(proj(*(v.begin() + i)), val); }); } #define DEFAULT_COMP less<> #else 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 #endif template inline constexpr ull MASK(T k) { return (1ULL << k) - 1ULL; } #if __cplusplus < 202002L inline constexpr ull bit_width(ull x) { return x == 0 ? 0 : 64 - __builtin_clzll(x); } inline constexpr ull countr_zero(ull x) { assert(x != 0); return __builtin_ctzll(x); } inline constexpr ull popcount(ull x) { return __builtin_popcountll(x); } #else 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); } #endif #define dump(...) #define oj(...) __VA_ARGS__ 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(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_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++]; } if constexpr (is_signed::value || is_same_v) { if (minus) x = -x; } } void rd1(ll &x) { rd1_integer(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); } 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; } void wt1(int x) { wt1_integer(x); } template , int> = 0> void wt1(T x) { wt1_integer(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 print() { wt1('\n'); } template void print(Head &&head, Tail &&... tail) { wt1(head); if (sizeof...(Tail)) wt1(' '); print(forward(tail)...); } } // namespace fastio 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...); } }; // namespace internal #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 VEC(T, n, ...) vc __VA_ARGS__; READVEC(n, __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; } }; // namespace internal 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(vc &v, const Add &add) { for (auto &vi : v) vi += add; } template void offset(vvc &v, const Add &add) { for (auto &vi : v) for (auto &vij : vi) vij += add; } template array, m> top(const vc> &vt) { const size_t n = vt.size(); array, m> tv; tv.fill(vc(n)); for (size_t i = 0; i < n; i++) for (size_t j = 0; j < m; j++) tv[j][i] = vt[i][j]; return tv; } template vc> top(const array, m> &tv) { if (tv.empty()) return {}; const size_t n = tv[0].size(); vc> vt(n); for (size_t j = 0; j < m; j++) { assert(tv[j].size() == n); for (size_t i = 0; i < n; i++) vt[i][j] = tv[j][i]; } return vt; } template pair, vc> top(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> top(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 top(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 top(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 randrange(U1 l, U2 r) { assert(T(l) < T(r)); return T(l) + mt() % (T(r) - T(l)); } namespace internal { constexpr ll powmod32_constexpr(ll x, ll n, int m) { if (m == 1) return 0; uint _m = (uint)m; ull r = 1; ull y = safemod(x, m); while (n) { if (n & 1) r = (r * y) % _m; y = (y * y) % _m; n >>= 1; } return r; } constexpr bool isprime32_constexpr(int 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; constexpr ll bases[3] = {2, 7, 61}; for (ll a : bases) { ll t = d; ll y = powmod32_constexpr(a, t, n); while (t != n - 1 && y != 1 && y != n - 1) { y = y * y % n; t <<= 1; } if (y != n - 1 && t % 2 == 0) return false; } return true; } template constexpr bool isprime32 = isprime32_constexpr(n); 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)); } }; } namespace internal { #define REF static_cast(*this) #define CREF static_cast(*this) #define VAL *static_cast(this) template struct modint_base { mint &operator+=(const mint &rhs) { mint &self = REF; self._v += rhs._v; if (self._v >= self.umod()) self._v -= self.umod(); return self; } mint &operator-=(const mint &rhs) { mint &self = REF; self._v -= rhs._v; if (self._v >= self.umod()) self._v += self.umod(); return self; } mint &operator/=(const mint &rhs) { mint &self = REF; return self = self * rhs.inv(); } mint &operator++() { mint &self = REF; self._v++; if (self._v == self.umod()) self._v = 0; return self; } mint &operator--() { mint &self = REF; if (self._v == 0) self._v = self.umod(); self._v--; return self; } mint operator++(int) { mint res = VAL; ++REF; return res; } mint operator--(int) { mint res = VAL; --REF; return res; } mint operator+() const { return VAL; } mint operator-() const { return mint() - VAL; } mint pow(ll n) const { assert(n >= 0); mint x = VAL, r = 1; while (n) { if (n & 1) r *= x; x *= x; n >>= 1; } return r; } 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 mint(lhs).eq(rhs); } friend bool operator!=(const mint &lhs, const mint &rhs) { return mint(lhs).neq(rhs); } private: bool eq(const mint &rhs) { return REF._v == rhs._v; } bool neq(const mint &rhs) { return REF._v != rhs._v; } }; } template , T>, int> = 0> void rd1(T &x) { ll a; fastio::rd1(a); x = a; } template , T>, int> = 0> void wt1(const T &x) { fastio::wt1(x.val()); } template constexpr tuple extgcd(const T &a, const 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}; } template struct static_modint : internal::modint_base> { using mint = static_modint; private: friend struct internal::modint_base>; uint _v; static constexpr uint umod() { return m; } static constexpr bool prime = internal::isprime32; public: static constexpr int mod() { return m; } static mint raw(int v) { mint x; x._v = v; return x; } static_modint() : _v(0) {} template static_modint(T v) { if constexpr (is_signed_v) { ll x = (ll)(v % (ll)(umod())); if (x < 0) x += umod(); _v = (uint)x; } else if constexpr (is_unsigned_v) { _v = (uint)(v % umod()); } else { static_assert(is_signed_v || is_unsigned_v, "Unsupported Type"); } } int val() const { return (int)_v; } mint& operator*=(const mint &rhs) { ull z = _v; z *= rhs._v; _v = (uint)(z % umod()); return *this; } mint inv() const { if (prime) { assert(_v != 0); return CREF.pow(umod() - 2); } else { auto [g, x, y] = extgcd(_v, m); assert(g == 1); return x; } } }; template struct dynamic_modint : internal::modint_base> { using mint = dynamic_modint; private: friend struct internal::modint_base>; uint _v; static internal::barrett32 bt; static uint umod() { return bt.umod(); } public: static int mod() { return (int)(bt.umod()); } static mint raw(int v) { mint x; x._v = v; return x; } dynamic_modint() : _v(0) {} template dynamic_modint(T v) { if constexpr (is_signed_v) { ll x = (ll)(v % (ll)(umod())); if (x < 0) x += umod(); _v = (uint)x; } else if constexpr (is_unsigned_v) { _v = (uint)(v % umod()); } else { static_assert(is_signed_v || is_unsigned_v, "Unsupported Type"); } } int val() const { return (int)_v; } mint& operator*=(const mint &rhs) { _v = bt.mul(_v, rhs._v); return *this; } mint inv() const { auto [g, x, y] = extgcd(_v, mod()); assert(g == 1); return x; } }; template internal::barrett32 dynamic_modint::bt(998244353); using modint1000000007 = static_modint<1000000007>; template struct is_static_modint : false_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 inline constexpr bool is_dynamic_modint_v = is_dynamic_modint::value; template inline constexpr bool is_modint_v = is_static_modint_v || is_dynamic_modint_v; using mint = modint1000000007; template struct CSR { protected: int n, m; vc start; vc elist; vc eid_to_elistid; struct Row { using iterator = typename vc::const_iterator; private: iterator begi, endi; public: Row(const iterator &begi, const iterator &endi) : begi(begi), endi(endi) {} inline iterator begin() const { return begi; } inline iterator end() const { return endi; } template inline I size() const { return endi - begi; } inline bool empty() const { return size() == 0; } inline T operator[](int i) const { return *(begi + i); } inline T at(int i) const { assert(0 <= i && i < size()); return *(begi + i); } inline T front() const { assert(!empty()); return *begi; } inline T back() const { assert(!empty()); return *prev(endi); } }; public: CSR() {} template CSR(int n, const vc> &ies) : n(n), m(ies.size()), start(n, 0), elist(m), eid_to_elistid(m) { fec([ i, e ] : ies) { assert(0 <= i && i < n); start[i]++; } start = cumlsum(start); auto cnt = start; repi(j, m) { cauto &[i, e] = ies[j]; int &k = cnt[i]; elist[k] = e; eid_to_elistid[j] = k; k++; } } CSR(const vvc &vv) : n(vv.size()), start(n + 1, 0) { m = 0; fec(row : vv) m += row.size(); elist.resize(m); eid_to_elistid.resize(m); int k = 0; for (int i = 0, j = 0; i < n; i++) { start[i] = k; fec(e : vv[i]) { elist[k] = e; eid_to_elistid[j++] = k; k++; } } start.back() = m; } Row operator[](int i) const { return Row(elist.begin() + start[i], elist.begin() + start[i + 1]); } Row at(int i) const { if (!(0 <= i && i < n)) return Row(elist.begin(), elist.begin()); return Row(elist.begin() + start[i], elist.begin() + start[i + 1]); } template I size() const { return n; } const T &find_by_eid(int eid) const { assert(0 <= eid && eid < m); return elist[eid_to_elistid[eid]]; } }; template struct Edge { int from, to; Cost cost; int index; Edge() : from(-1), to(-1), index(-1) {} Edge(int s, int t, Cost c, int i = -1) : from(s), to(t), cost(c), index(i) {} operator int() const { return to; } bool operator<(const Edge &rhs) const { return cost < rhs.cost; } Edge rev() const { return Edge(to, from, cost, index); } }; template struct Graph { using E = Edge; protected: int n, m; CSR g; public: Graph() {} template Graph(int n, const vc> &es, const Cost &dflt_cost = 1) : n(n), m(es.size()) { if constexpr (is_directed) { vc> edges(m); repi(i, m) { auto [u, v] = es[i]; assert(0 <= u && u < n); assert(0 <= v && v < n); edges[i] = {u, E(u, v, dflt_cost, i)}; } g = CSR(n, edges); } else { vc> edges(2 * m); repi(i, m) { auto [u, v] = es[i]; assert(0 <= u && u < n); assert(0 <= v && v < n); edges[2 * i] = {u, E(u, v, dflt_cost, i)}; edges[2 * i + 1] = {v, E(v, u, dflt_cost, i)}; } g = CSR(n, edges); } } template Graph(int n, const vc> &es) : n(n), m(es.size()) { if constexpr (is_directed) { vc> edges(m); repi(i, m) { auto [u, v, w] = es[i]; assert(0 <= u && u < n); assert(0 <= v && v < n); edges[i] = {u, E(u, v, w, i)}; } g = CSR(n, edges); } else { vc> edges(2 * m); repi(i, m) { auto [u, v, w] = es[i]; assert(0 <= u && u < n); assert(0 <= v && v < n); edges[2 * i] = {u, E(u, v, w, i)}; edges[2 * i + 1] = {v, E(v, u, w, i)}; } g = CSR(n, edges); } } template I size() const { return n; } E get_edge(int eid) const { if constexpr (is_directed) return g.find_by_eid(eid); else { E e = g.find_by_eid(eid * 2); return e.from > e.to ? e.rev() : e; } } }; template using GraphDirected = Graph; template struct MyQueue { private: vc d; int pos = 0; public: void reserve(int n) { d.reserve(n); } template I size() const { return SZ(d) - pos; } bool empty() const { return pos == SZ(d); } void push(const T &t) { d.eb(t); } T front() const { return d[pos]; } T &front() { return d[pos]; } void clear() { d.clear(); pos = 0; } void pop() { pos++; } T operator[](int i) const { return d[pos + i]; } T &operator[](int i) { return d[pos + i]; } T at(int i) const { assert(0 <= i && i < size()); return d[pos + i]; } T &at(int i) { assert(0 <= i && i < size()); return d[pos + i]; } vc content() { return {d.begin() + pos, d.end()}; } }; template struct Monoid { using S = S_; static constexpr auto op = op_; static constexpr auto e = e_; }; template struct Group { using S = S_; static constexpr auto op = op_; static constexpr auto e = e_; static constexpr auto inv = inv_; }; template struct SemiRingFromMonoidMonoid { static_assert(is_same_v, "Madd::S and Mmul::S must be identical"); using S = typename Madd::S; static constexpr auto add = Madd::op; static constexpr auto e0 = Madd::e; static constexpr auto mul = Mmul::op; static constexpr auto e1 = Mmul::e; }; template struct RingFromGroupMonoid { static_assert(is_same_v, "Gadd::S and Mmul::S must be identical"); using S = typename Gadd::S; static constexpr auto add = Gadd::op; static constexpr auto e0 = Gadd::e; static constexpr auto minus = Gadd::inv; static constexpr auto mul = Mmul::op; static constexpr auto e1 = Mmul::e; }; template struct FieldFromGroupGroup { static_assert(is_same_v, "Gadd::S and Gmul::S must be identical"); using S = typename Gadd::S; static constexpr auto add = Gadd::op; static constexpr auto e0 = Gadd::e; static constexpr auto minus = Gadd::inv; static constexpr auto mul = Gmul::op; static constexpr auto e1 = Gmul::e; static constexpr auto inv = Gmul::inv; }; template struct MonoidMul { using S = T; static constexpr S op(S a, S b) { return a * b; } static constexpr S e() { return 1; } }; template struct GroupAddSub { using S = T; static constexpr S op(S a, S b) { return a + b; } static constexpr S e() { return S(0); } static constexpr S inv(S a) { return -a; } }; template struct GroupMulDiv { using S = T; static constexpr S op(S a, S b) { return a * b; } static constexpr S e() { return S(1); } static constexpr S inv(S a) { return S(1) / a; } }; template using FieldAddSubMulDiv = FieldFromGroupGroup, GroupMulDiv>; template vc berlekamp_massey(const vc &a) { using S = typename F::S; const int n = a.size(); vc b, c; int pos = -1; S x = F::e0(); repi(i, n) { const int d = c.size(); S y = a[i]; repi(j, d) y = F::add(y, F::minus(F::mul(c[j], a[i - 1 - j]))); if (y == F::e0()) continue; if (c.empty()) { c.assign(i + 1, F::e0()); pos = i; x = y; continue; } S z = F::mul(y, F::inv(x)); int d2 = i - pos + b.size(); vc tmp; if (d2 >= d) { tmp = c; c.resize(d2, F::e0()); } c[i - 1 - pos] = F::add(c[i - 1 - pos], z); repi(j, b.size()) c[i - pos + j] = F::add(c[i - pos + j], F::minus(F::mul(z, b[j]))); if (d2 >= d) pos = i, x = y, b = tmp; } c.insert(c.begin(), F::minus(F::e1())); return c; } namespace bbla { template mint random_sample_mint() { return randrange(1, mint::mod()); } template )> vc minimal_polynomial(int n, const LinearMap &linear_map, const RandomSample &random_sample = random_sample_mint) { using S = typename F::S; assert(n > 0); vc u(n, F::e0()), v(n, F::e0()); repi(j, n) u[j] = random_sample(), v[j] = random_sample(); vc a(2 * n + 1, F::e0()); repi(i, 2 * n + 1) { repi(j, n) a[i] = F::add(a[i], F::mul(u[j], v[j])); linear_map(v); } return reversed(berlekamp_massey(a)); } template )> typename F::S det(int n, const LinearMap &linear_map, const RandomSample &random_sample = random_sample_mint) { using S = typename F::S; while (true) { vc d(n); repi(i, n) d[i] = random_sample(); auto linear_map_ad = [&](vc &v) { repi(i, n) v[i] = F::mul(v[i], d[i]); linear_map(v); }; auto m = minimal_polynomial(n, linear_map_ad, random_sample); if (m[0] == F::e0()) return F::e0(); if (SZ(m) != n + 1) continue; S detd = F::e1(); fec(di : d) detd = F::mul(detd, di); S res = F::mul(m[0], F::inv(detd)); return n & 1 ? res : F::minus(res); } } } // namespace bbla namespace internal { constexpr ll powmod64_constexpr(ll x, ll n, ll m) { if (m == 1) return 0; ull _m = (ull)m; ull r = 1; ull y = safemod(x, m); while (n) { u128 y128(y); if (n & 1) r = (y128 * r) % _m; y = (y128 * y) % _m; n >>= 1; } return r; } constexpr bool isprime64_constexpr(ll n) { if (n <= INT_MAX) return isprime32_constexpr(n); if (n % 2 == 0) return false; ll d = n - 1; while (d % 2 == 0) d /= 2; constexpr ll bases[7] = {2, 325, 9375, 28178, 450775, 9780504, 1795265022}; for (ll a : bases) { ll t = d; ll y = powmod64_constexpr(a, t, n); while (t != n - 1 && y != 1 && y != n - 1) { y = (u128(y) * y) % n; t <<= 1; } if (y != n - 1 && t % 2 == 0) return false; } return true; } template constexpr bool isprime64 = isprime64_constexpr(n); 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; // m == 2^b * mx, mx is odd imx = inv64(mx); d = powmod64_constexpr((mx + 1) / 2, b, mx); // 2^{-b} mod mx u128 sq = -u128(mx) % mx; // 2^128 mod mx q = (1 + (((sq - 1) * d) << b)) % m; } ull umod() const { return m; } ull reduce(u128 x) const { ull p = x & MASK(b); // x mod 2^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 static_modint64 : internal::modint_base> { using mint = static_modint64; private: friend struct internal::modint_base>; ull _v; static constexpr ull umod() { return m; } static constexpr bool prime = internal::isprime64; public: static constexpr ll mod() { return m; } static mint raw(ll v) { mint x; x._v = v; return x; } static_modint64() : _v(0) {} template static_modint64(T v) { if constexpr (is_unsigned_v) { _v = (ull)(v % umod()); } else { ll x = (ll)(v % (ll)(umod())); if (x < 0) x += umod(); _v = (ull)x; } } ll val() const { return (ll)_v; } mint& operator*=(const mint &rhs) { u128 z = _v; z *= rhs._v; _v = (ull)(z % umod()); return *this; } mint inv() const { if (prime) { assert(_v != 0); return CREF.pow(umod() - 2); } else { auto [g, x, y] = extgcd(_v, m); assert(g == 1); return x; } } }; template struct dynamic_modint64_odd : internal::modint_base> { using mint = dynamic_modint64_odd; private: friend struct internal::modint_base>; ull _v; // montgomery expression static internal::montgomery64odd mg; static ull umod() { return mg.umod(); } public: static ll mod() { return (ll)(mg.umod()); } dynamic_modint64_odd() : _v(0) {} dynamic_modint64_odd(i128 v) { _v = mg.inv_reduce(v); } ll val() const { return (ll)mg.reduce(_v); } mint& operator*=(const mint &rhs) { _v = mg.reduce(u128(_v) * rhs._v); return *this; } mint inv() const { auto [g, x, y] = extgcd(val(), mod()); assert(g == 1); return x; } }; template internal::montgomery64odd dynamic_modint64_odd::mg((1LL << 61) - 1); template struct dynamic_modint64 : internal::modint_base> { using mint = dynamic_modint64; private: friend struct internal::modint_base>; ull _v; // montgomery expression static internal::montgomery64 mg; static ull umod() { return mg.umod(); } public: static ll mod() { return (ll)(mg.umod()); } static void set_mod(ll m) { assert(m >= 1); mg = internal::montgomery64(m); } dynamic_modint64() : _v(0) {} dynamic_modint64(i128 v) { _v = mg.inv_reduce(v); } ll val() const { return (ll)mg.reduce(_v); } mint& operator*=(const mint &rhs) { _v = mg.reduce(u128(_v) * rhs._v); return *this; } mint inv() const { auto [g, x, y] = extgcd(val(), mod()); assert(g == 1); return x; } }; template internal::montgomery64 dynamic_modint64::mg((1LL << 61) - 1); template struct is_static_modint64 : false_type {}; template struct is_static_modint64> : true_type {}; template inline constexpr bool is_static_modint64_v = is_static_modint64::value; template struct is_dynamic_modint64 : false_type {}; template struct is_dynamic_modint64> : true_type {}; template inline constexpr bool is_dynamic_modint64_v = is_dynamic_modint64::value; template inline constexpr bool is_modint64_v = is_static_modint64_v || is_dynamic_modint64_v; template struct Matrix : vvc { using S = typename F::S; using M = Matrix; using V = vc; using vvc::vector; using vvc::operator=; Matrix(int n, int m, const S &diag = F::e0(), const S &non_diag = F::e0()) { *this = vvc(n, vc(m, non_diag)); repi(i, min(n, m))(*this)[i][i] = diag; } Matrix(const vvc &a) { *this = a; } template pair shape() const { const int n = (*this).size(); if (n == 0) return {0, 0}; const int m = (*this)[0].size(); return {n, m}; } M operator-() const { auto [n, m] = shape(); M res(*this); repi(i, n) repi(j, m) res[i][j] = F::minus(res[i][j]); return res; } M &operator+=(const M &b) { assert(shape() == b.shape()); auto [n, m] = shape(); repi(i, n) repi(j, m) (*this)[i][j] = F::add((*this)[i][j], b[i][j]); return *this; } M &operator-=(const M &b) { return *this += F::minus(b); } M &operator*=(const S &x) { auto [n, m] = shape(); repi(i, n) repi(j, m) (*this)[i][j] = F::mul((*this)[i][j], x); return *this; } M &operator/=(const S &x) { return *this *= F::inv(x); } V operator*(const V &v) const { auto [n, m] = shape(); assert(SZ(v) == m); V res(n, F::e0()); repi(i, n) { S sm = F::e0(); repi(j, m) sm = F::add(sm, F::mul((*this)[i][j], v[j])); res[i] = sm; } return res; } M operator*(const M &b) const { auto [n, m] = shape(); auto [m_, p] = b.shape(); assert(m == m_); M res(n, p); repi(ii, 0, n, BS) repi(kk, 0, m, BS) repi(jj, 0, p, BS) { repi(i, ii, min(ii + BS, n)) repi(k, kk, min(kk + BS, m)) { S aik = (*this)[i][k]; if (aik == F::e0()) continue; repi(j, jj, min(jj + BS, p)) res[i][j] = F::add(res[i][j], F::mul(aik, b[k][j])); } } return res; } template M pow(T k) const { auto [n, m] = shape(); assert(n == m); M res(n, n, F::e1()), tmp(*this); while (k > 0) { if (k & 1) res *= tmp; tmp *= tmp; k >>= 1; } return res; } M operator+(const M &a) const { return M(*this) += a; } M operator-(const M &a) const { return M(*this) -= a; } M operator*(const S &x) const { return M(*this) *= x; } M operator/(const S &x) const { return M(*this) /= x; } M &operator*=(const M &a) { return *this = *this * a; } template tuple row_reduction(bool rref = false) const { auto [n, m] = shape(); M a(*this); I rk = 0; S de = F::e1(); for (int i = 0, j = 0; i < n && j < m; j++) { repi(k, i, n) { if (a[k][j] != F::e0()) { swap(a[k], a[i]); if (k != i) de = F::minus(de); break; } } if (a[i][j] == F::e0()) { de = 0; continue; } de = F::mul(de, a[i][j]); S aij_inv = F::inv(a[i][j]); repi(l, m) a[i][l] = F::mul(a[i][l], aij_inv); if (rref) { repi(k, i) { S akj = a[k][j]; repi(l, m) a[k][l] = F::add(a[k][l], F::minus(F::mul(a[i][l], akj))); } } repi(k, i + 1, n) { S akj = a[k][j]; repi(l, m) a[k][l] = F::add(a[k][l], F::minus(F::mul(a[i][l], akj))); } i++; rk++; } return {a, rk, de}; } S det() const { auto [n, m] = shape(); assert(n == m); if (n == 0) return 1; if constexpr (is_modint_v || is_modint64_v) { S cand = (*this)[0][0]; int cnt = 0; repi(i, n) repi(j, n) { S x = (*this)[i][j]; if (cnt == 0) cand = x, cnt = 1; else if (cand == x) cnt++; else cnt--; } int k = n * n; repi(i, n) repi(j, n) if ((*this)[i][j] == cand) k--; if (k < n * n / 8) return det_sparse(cand); } return get<2>(row_reduction()); } template )> S det_sparse(const S &majority = F::e0(), const RandomSample &random_sample = bbla::random_sample_mint) const { auto [n, m] = shape(); assert(n == m); vc> elms; repi(i, n) repi(j, n) { if ((*this)[i][j] != majority) elms.eb(i, j); } auto linear_map = [&](vc &x) { S sm = F::e0(); fec(xi : x) sm = F::add(sm, xi); vc y(n, F::mul(majority, sm)); fec([ i, j ] : elms) y[i] = F::add(y[i], F::mul(F::add((*this)[i][j], F::minus(majority)), x[j])); x = y; }; return bbla::det(n, linear_map, random_sample); } pair inv() const { auto [n, m] = shape(); assert(n == m); M a(n, 2 * n); repi(i, n) repi(j, n) a[i][j] = (*this)[i][j]; repi(i, n) a[i][n + i] = F::e1(); M b = get<0>(a.row_reduction(true)); repi(i, n) if (b[i][i] == F::e0()) return {false, {}}; M res(n, n); repi(i, n) repi(j, n) res[i][j] = b[i][n + j]; return {true, res}; } }; template struct Binomial { private: static decltype(T::mod()) mod; static vc fac_, finv_, inv_; public: static void reserve(int n) { if (mod != T::mod()) { mod = T::mod(); fac_ = {1, 1}, finv_ = {1, 1}, inv_ = {0, 1}; } int i = fac_.size(); chmin(n, T::mod() - 1); if (n < i) return; fac_.resize(n + 1), finv_.resize(n + 1), inv_.resize(n + 1); for (; i <= n; i++) { 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 fac(int n) { assert(n >= 0); if (n >= T::mod()) return 0; reserve(n); return fac_[n]; } static T inv(T n) { assert(n != 0); reserve(n.val()); return inv_[n.val()]; } }; template decltype(T::mod()) Binomial::mod{}; template vc Binomial::fac_{}; template vc Binomial::finv_{}; template vc Binomial::inv_{}; template mint count_spanning_trees_directed(const vvc &g, int r) { const int n = g.size(); if (n == 0) return 1; repi(i, n) assert(SZ(g[i]) == n); Matrix> mat(n - 1, n - 1); repi(i, n) repi(j, n) { if (i == j) continue; const int u = i < r ? i : i - 1; const int v = j < r ? j : j - 1; if (i != r && j != r) mat[u][v] = -g[i][j]; if (j != r) mat[v][v] += g[i][j]; } return mat.det(); } template mint count_eularian_circuits(const vvc &g) { const int n = g.size(); repi(i, n) assert(SZ(g[i]) == n); vc indeg(n, 0), outdeg(n, 0); repi(i, n) repi(j, n) indeg[j] += g[i][j], outdeg[i] += g[i][j]; int k = 0; vc id(n, -1); repi(i, n) if (indeg[i] != 0 || outdeg[i] != 0) id[i] = k++; vvc h(k, vc(k, 0)); repi(i, n) repi(j, n) { if (g[i][j] == 0) continue; h[id[i]][id[j]] = g[i][j]; } if (k == 0) return 1; repi(i, n) if (indeg[i] != outdeg[i]) return 0; vb visited(k, false); MyQueue que; que.push(0); while (!que.empty()) { int i = que.front(); que.pop(); repi(j, k) { if (h[i][j] == 0) continue; if (visited[j]) continue; visited[j] = true; que.push(j); } } if (count(ALL(visited), false) > 0) return 0; mint res = count_spanning_trees_directed(h, 0); repi(i, n) if (indeg[i] != 0) res *= Binomial::fac(indeg[i] - 1); return res; } template mint count_eularian_trails(const vvc &g) { const int n = g.size(); repi(i, n) assert(SZ(g[i]) == n); vc indeg(n, 0), outdeg(n, 0); repi(i, n) repi(j, n) indeg[j] += g[i][j], outdeg[i] += g[i][j]; const int m = SUM(indeg); if (m == 0) return 1; int u = -1, v = -1; repi(i, n) { if (indeg[i] - outdeg[i] == 1) { if (u != -1) return 0; u = i; } else if (indeg[i] - outdeg[i] == -1) { if (v != -1) return 0; v = i; } else { if (indeg[i] - outdeg[i] != 0) return 0; } } if (u == -1 && v == -1) return count_eularian_circuits(g) * m; else if (u != -1 && v != -1) { auto h = g; h[u][v]++; return count_eularian_circuits(h); } else return 0; } void init() { oj(mt.seed(random_device()())); } void main2() { LL(N, M); VEC(pll, M, AB); offset(AB, pll{-1, -1}); vvc G(N, vc(N, 1)); fec([ a, b ] : AB) G.at(a).at(b) = 0; PRINT(count_eularian_trails(G)); } void test() { } template struct Main { Main() { cauto CERR = [](string val, string color) { string s = "\033[" + color + "m" + val + "\033[m"; /* コードテストで確認する際にコメントアウトを外す cerr << val; //*/ }; 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() {}