#pragma region Macros #pragma GCC optimize("O3,unroll-loops") #pragma GCC target("sse,sse2,sse3,ssse3,sse4,fma,mmx,abm,bmi,bmi2,popcnt,lzcnt") #pragma GCC target("avx2") // CF, CodeChef, HOJ ではコメントアウト #include #include using namespace atcoder; using namespace std; using namespace __gnu_pbds; // #include // #include // namespace mp = boost::multiprecision; // using Bint = mp::cpp_int; // using Bdouble = mp::number>; // Bdouble Beps = 0.00000000000000000000000000000001; // 1e-32 // const bool equals(Bdouble a, Bdouble b) { return mp::fabs(a - b) < Beps; } #define pb emplace_back // #define int ll #define endl '\n' // #define sqrt __builtin_sqrtl // #define cbrt __builtin_cbrtl // #define hypot __builtin_hypotl using ll = long long; using ld = long double; const ld PI = acosl(-1); const int INF = 1 << 30; const ll INFL = 1LL << 61; // const int MOD = 998244353; const int MOD = 1000000007; const ld EPS = 1e-10; const bool equals(ld a, ld b) { return fabs((a) - (b)) < EPS; } const vector dx = {0, 1, 0, -1, 1, 1, -1, -1, 0}; // → ↓ ← ↑ ↘ ↙ ↖ ↗ 自 const vector dy = {1, 0, -1, 0, 1, -1, -1, 1, 0}; #define EC int struct Edge { int from, to; EC cost; Edge() {} // Edge() : from(-1), to(-1), cost(-1) {} Edge(int to, EC cost) : to(to), cost(cost) {} Edge(int from, int to, EC cost) : from(from), to(to), cost(cost) {} bool operator ==(const Edge &e) { return this->from == e.from && this->to == e.to && this->cost == e.cost; } bool operator !=(const Edge &e) { return this->from != e.from or this->to != e.to or this->cost != e.cost; } bool operator <(const Edge &e) { return this->cost < e.cost; } bool operator >(const Edge &e) { return this->cost > e.cost; } }; chrono::system_clock::time_point start; __attribute__((constructor)) void constructor() { ios::sync_with_stdio(false); cin.tie(nullptr); cout << fixed << setprecision(10); start = chrono::system_clock::now(); } random_device seed_gen; mt19937_64 rng(seed_gen()); uniform_int_distribution dist_x(0, 1e9); struct RNG { unsigned Int() { return dist_x(rng); } unsigned Int(unsigned l, unsigned r) { return dist_x(rng) % (r - l + 1) + l; } ld Double() { return ld(dist_x(rng)) / 1e9; } } rnd; namespace bit_function { using i64 = ll; // using i64 = uint64_t; // bit演算, x==0の場合は例外処理した方がよさそう. 区間は [l, r) i64 lrmask(int l, int r) { return (1LL << r) - (1LL << l); } i64 sub_bit(i64 x, int l, int r) { i64 b = x & ((1LL << r) - (1LL << l)); return b >> l; } // r溢れ可 i64 bit_width(i64 x) { return 64 - __builtin_clzll(x) + (x == 0); } i64 popcount(i64 x) { return __builtin_popcountll(x); } i64 popcount(i64 x, int l, int r) { return __builtin_popcountll(sub_bit(x, l, r)); } i64 unpopcount(i64 x) { return bit_width(x) - __builtin_popcountll(x); } // 最上位bitより下のみ i64 unpopcount(i64 x, int l, int r) { return r - l - __builtin_popcountll(sub_bit(x, l, r)); } // 最上位bitより上も含まれうる bool is_pow2(i64 x) { return __builtin_popcountll(x) == 1; } // xが負のときは常にfalse bool is_pow4(i64 x) { return __builtin_popcountll(x) == 1 && __builtin_ctz(x) % 2 == 0; } //bool is_pow4(ll x) { return __builtin_popcountll(x) == 1 && (x&0x55555555); } int top_bit(i64 x) { return 63 - __builtin_clzll(x);} // 2^kの位 (x > 0) int bot_bit(i64 x) { return __builtin_ctzll(x);} // 2^kの位 (x > 0) int next_bit(i64 x, int k) { // upper_bound x >>= (k + 1); int pos = k + 1; while (x > 0) { if (x & 1) return pos; x >>= 1; pos++; } return -1; } int prev_bit(i64 x, int k) { // k = min(k, bit_width(x)); ? int pos = 0; while (x > 0 && pos < k) { if (x & 1) { if (pos < k) return pos; } x >>= 1; pos++; } return -1; } int kth_bit(i64 x, int k) { // kは1-indexed int pos = 0, cnt = 0; while (x > 0) { if (x & 1) { cnt++; if (cnt == k) return pos; } x >>= 1; pos++; } return -1; } i64 msb(i64 x) { if (x == 0) return 0; return 1LL << (63 - __builtin_clzll(x)); } // mask i64 lsb(i64 x) { return (x & -x); } // mask int countl_zero(i64 x) { return __builtin_clzll(x); } int countl_one(i64 x) { // countl_oneと定義が異なるので注意 i64 ret = 0, k = 63 - __builtin_clzll(x); while (k != -1 && (x & (1LL << k))) { k--; ret++; } return ret; } int countr_zero(i64 x) { return __builtin_ctzll(x); } // x=0のとき64 int countr_one(i64 x) { int ret = 0; while (x & 1) { x >>= 1; ret++; } return ret; } // int countr_one(ll x) { return __builtin_popcount(x ^ (x & -~x)); i64 l_one(i64 x) { // 最上位で連なってる1のmask if (x == 0) return 0; i64 ret = 0, k = 63 - __builtin_clzll(x); while (k != -1 && (x & (1LL << k))) { ret += 1LL << k; k--; } return ret; } int floor_log2(i64 x) { return 63 - __builtin_clzll(x); } // top_bit int ceil_log2(i64 x) { return 64 - __builtin_clzll(x - 1); } i64 bit_floor(i64 x) { if (x == 0) return 0; return 1LL << (63 - __builtin_clzll(x)); } // msb i64 bit_ceil(i64 x) { if (x == 0) return 0; return 1LL << (64 - __builtin_clzll(x - 1)); } i64 rotl(i64 x, int k) { // 有効bit内でrotate. オーバーフロー注意 i64 w = bit_width(x); k %= w; return ((x << k) | (x >> (w - k))) & ((1LL << w) - 1); } // i64 rotl(i64 x, i64 l, i64 m, i64 r) {} i64 rotr(i64 x, int k) { i64 w = bit_width(x); k %= w; return ((x >> k) | (x << (w - k))) & ((1LL << w) - 1); } // i64 rotr(i64 x, i64 l, i64 m, i64 r) {} i64 bit_reverse(i64 x) { // 有効bit内で左右反転 i64 r = 0, w = bit_width(x); for (i64 i = 0; i < w; i++) r |= ((x >> i) & 1) << (w - i - 1); return r; } // i64 bit_reverse(i64 x, int l, int r) {} bool is_palindrome(i64 x) { return x == bit_reverse(x); } bool is_palindrome(i64 x, int l, int r) { i64 b = sub_bit(x, l, r); return b == bit_reverse(b); } i64 concat(i64 a, i64 b) { return (a << bit_width(b)) | b; } // オーバーフロー注意 i64 erase(i64 x, int l, int r) { return x >> r << l | x & ((1LL << l) - 1); } // [l, r) をカット i64 hamming(i64 a, i64 b) { return __builtin_popcountll(a ^ b); } i64 hamming(i64 a, i64 b, int l, int r) { return __builtin_popcountll(sub_bit(a, l, r) ^ sub_bit(b, l, r)); } i64 compcount(i64 x) { return (__builtin_popcountll(x ^ (x >> 1)) + (x & 1)) / 2; } i64 compcount2(i64 x) { return compcount(x & (x >> 1)); } // 長さ2以上の連結成分の個数 i64 adjacount(i64 x) { return __builtin_popcountll(x & (x >> 1)); } // 隣接する1のペアの個数 i64 next_combination(i64 x) { i64 t = x | (x - 1); return (t + 1) | (((~t & -~t) - 1) >> (__builtin_ctzll(x) + 1)); } } using namespace bit_function; namespace util_function { namespace Std = std; __int128_t POW(__int128_t x, int n) { __int128_t ret = 1; assert(n >= 0); if (x == 1 or n == 0) ret = 1; else if (x == -1 && n % 2 == 0) ret = 1; else if (x == -1) ret = -1; else if (n % 2 == 0) { // assert(x < INFL); ret = POW(x * x, n / 2); } else { // assert(x < INFL); ret = x * POW(x, n - 1); } return ret; } int per(int x, int y) { // x = qy + r (0 <= r < y) を満たすq assert(y != 0); if (x >= 0 && y > 0) return x / y; if (x >= 0 && y < 0) return x / y - (x % y < 0); if (x < 0 && y < 0) return x / y + (x % y < 0); return x / y - (x % y < 0); // (x < 0 && y > 0) } int mod(int x, int y) { // x = qy + r (0 <= r < y) を満たすr assert(y != 0); return x - y * per(x, y); } // https://yukicoder.me/problems/no/2781 int floor(int x, int y) { // (ld)x / y 以下の最大の整数 assert(y != 0); if (y < 0) x = -x, y = -y; return x >= 0 ? x / y : (x + 1) / y - 1; } int ceil(int x, int y) { // (ld)x / y 以上の最小の整数 assert(y != 0); if (y < 0) x = -x, y = -y; return x > 0 ? (x - 1) / y + 1 : x / y; } int round(int x, int y) { // (ld)x / y を小数第1位について四捨五入 assert(y != 0); return (x * 2 + y) / (y * 2); } int round(int x, int y, int k) { // (ld)x / y を10^kの位に関して四捨五入 assert(y != 0 && k >= 0); if (k == 0) return (x * 2 + y) / (y * 2); x /= y * POW(10, k - 1); if (x % 10 >= 5) return (x + 10 - x % 10) * POW(10, k - 1); return x * POW(10, k - 1); } int round2(int x, int y) { // 五捨五超入 // 未verify assert(y != 0); if (y < 0) y = -y, x = -x; int z = x / y; if ((z * 2 + 1) * y <= y * 2) z++; return z; } ld round(ld x, int k) { // xを10^kの位に関して四捨五入. // x += EPS; ld d = pow(10, -k); return Std::round(x * d) / d; } ld floor(ld x, int k) { // xを10^kの位に関してflooring // x += EPS; ld d = pow(10, -k); return Std::floor(x * d) / d; // 未verify } ld ceil(ld x, int k) { // xを10^kの位に関してceiling // x -= EPS; ld d = pow(10, -k); return Std::ceil(x * d) / d; // 未verify } // int kth(int x, int y, int k) { // x / yの10^kの位の桁 // } int floor(ld x, ld y) { // 誤差対策TODO assert(!equals(y, 0)); return Std::floor(x / y); // floor(x) = ceil(x - 1) という話も } int ceil(ld x, ld y) { // 誤差対策TODO // ceil(p/q) = -floor(-(p/q))らしい assert(!equals(y, 0)); return Std::ceil(x / y); // ceil(x) = floor(x + 1) } int perl(ld x, ld y) { // x = qy + r (0 <= r < y, qは整数) を満たす q // 未verify. 誤差対策TODO. EPS外してもいいかも。 assert(!equals(y, 0)); if (x >= 0 && y > 0) return Std::floor(x / y)+EPS; if (x >= 0 && y < 0) return -Std::floor(x / fabs(y)); if (x < 0 && y < 0) return Std::floor(x / y) + (x - Std::floor(x/y)*y < -EPS); return Std::floor(x / y) - (x - Std::floor(x/y)*y < -EPS); // (x < 0 && y > 0) } ld modl(ld x, ld y) { // x = qy + r (0 <= r < y, qは整数) を満たす r // 未verify. 誤差対策TODO. -0.0が返りうる。 assert(!equals(y, 0)); if (x >= 0) return x - fabs(y)*fabs(per(x, y)); return x - fabs(y)*floor(x, fabs(y)); } int seisuu(ld x) { return (int)x; } // 整数部分. 誤差対策TODO int modf(ld x) { if (x < 0) return ceill(x); else return floorl(x); } // 正なら+EPS, 負なら-EPSしてから、文字列に直して小数点以下を捨てる? int seisuu(int x, int y) { assert(y != 0); return x / y; } int seisuu(ld x, ld y) { // 誤差対策TODO assert(!equals(y, 0)); return (int)(x / y); } int floor_log(int base, int x) { assert(base >= 2); int ret = 0, now = 1; while (now <= x) { now *= base; if (now <= x) ret++; } return ret; } int ceil_log(int base, int x) { assert(base >= 2); int ret = 0, now = 1; while (now < x) { now *= base; ret++; } return ret; } template pair max(const pair &a, const pair &b) { if (a.first > b.first or a.first == b.first && a.second > b.second) return a; return b; } template pair min(const pair &a, const pair &b) { if (a.first < b.first or a.first == b.first && a.second < b.second) return a; return b; } template bool chmax(T &a, const T &b) { if (a < b) { a = b; return true; } return false; } template bool chmin(T &a, const T &b) { if (a > b) { a = b; return true; } return false; } template bool chmax(pair &a, const pair &b) { if (a.first < b.first or a.first == b.first && a.second < b.second) { a = b; return true; } return false; } template bool chmin(pair &a, const pair &b) { if (a.first > b.first or a.first == b.first && a.second > b.second) { a = b; return true; } return false; } template T mid(T a, T b, T c) { // 誤差対策TODO return a + b + c - Std::max({a, b, c}) - Std::min({a, b, c}); } template void Sort(T& a, T& b, T& c, Args&... args) { vector vec = {a, b, c, args...}; sort(vec.begin(), vec.end()); auto it = vec.begin(); a = *it++; b = *it++; c = *it++; int dummy[] = { (args = *it++, 0)... }; static_cast(dummy); } template void Sortr(T& a, T& b, T& c, Args&... args) { vector vec = {a, b, c, args...}; sort(vec.rbegin(), vec.rend()); auto it = vec.begin(); a = *it++; b = *it++; c = *it++; int dummy[] = { (args = *it++, 0)... }; static_cast(dummy); } template void sort(vector &A, vector &B) { vector> P(A.size()); for (int i = 0; i < A.size(); i++) P[i] = {A[i], B[i]}; sort(P.begin(), P.end()); for (int i = 0; i < A.size(); i++) A[i] = P[i].first, B[i] = P[i].second; } istream &operator >>(istream &is, __int128_t& x) { string S; is >> S; __int128_t ret = 0; int f = 1; if (S[0] == '-') f = -1; for (int i = 0; i < S.length(); i++) if ('0' <= S[i] && S[i] <= '9') ret = ret * 10 + S[i] - '0'; x = ret * f; return (is); } ostream &operator <<(ostream &os, __int128_t x) { ostream::sentry s(os); if (s) { __uint128_t tmp = x < 0 ? -x : x; char buffer[128]; char *d = end(buffer); do { --d; *d = "0123456789"[tmp % 10]; tmp /= 10; } while (tmp != 0); if (x < 0) { --d; *d = '-'; } int len = end(buffer) - d; if (os.rdbuf()->sputn(d, len) != len) os.setstate(ios_base::badbit); } return os; } __int128_t sto128(const string &S) { __int128_t ret = 0; int f = 1; if (S[0] == '-') f = -1; for (int i = 0; i < S.length(); i++) if ('0' <= S[i] && S[i] <= '9') ret = ret * 10 + S[i] - '0'; return ret * f; } __int128_t gcd(__int128_t a, __int128_t b) { return b ? gcd(b, a % b) : a; } __int128_t lcm(__int128_t a, __int128_t b) { return a / gcd(a, b) * b; // lcmが__int128_tに収まる必要あり } string to_string(double x, int k) { // 小数第k+1を四捨五入して小数第k位までを出力 // 切り捨てがほしい場合は to_string(x, k+1) として pop_back() すればよい? ostringstream os; os << fixed << setprecision(k) << x; return os.str(); } string to_string(__int128_t x) { string ret = ""; if (x < 0) { ret += "-"; x *= -1; } while (x) { ret += (char)('0' + x % 10); x /= 10; } reverse(ret.begin(), ret.end()); return ret; } string to_string(char c) { string s = ""; s += c; return s; } } using namespace util_function; struct custom_hash { static uint64_t splitmix64(uint64_t x) { x += 0x9e3779b97f4a7c15; x = (x ^ (x >> 30)) * 0xbf58476d1ce4e5b9; x = (x ^ (x >> 27)) * 0x94d049bb133111eb; return x ^ (x >> 31); } size_t operator()(uint64_t x) const { static const uint64_t FIXED_RANDOM = chrono::steady_clock::now().time_since_epoch().count(); return splitmix64(x + FIXED_RANDOM); } }; template size_t HashCombine(const size_t seed,const T &v) { return seed^(hash()(v)+0x9e3779b9+(seed<<6)+(seed>>2)); } template struct hash>{ size_t operator()(const pair &keyval) const noexcept { return HashCombine(hash()(keyval.first), keyval.second); } }; template struct hash>{ size_t operator()(const vector &keyval) const noexcept { size_t s=0; for (auto&& v: keyval) s=HashCombine(s,v); return s; } }; template struct HashTupleCore{ template size_t operator()(const Tuple &keyval) const noexcept{ size_t s=HashTupleCore()(keyval); return HashCombine(s,get(keyval)); } }; template <> struct HashTupleCore<0>{ template size_t operator()(const Tuple &keyval) const noexcept{ return 0; } }; template struct hash>{ size_t operator()(const tuple &keyval) const noexcept { return HashTupleCore>::value>()(keyval); } }; template class Compress { public: int sz = 0; vector uniqV; Compress() {} template Compress(const Vecs&... vecs) { (uniqV.insert(uniqV.end(), vecs.begin(), vecs.end()), ...); sort(uniqV.begin(), uniqV.end()); uniqV.erase(unique(uniqV.begin(), uniqV.end()), uniqV.end()); sz = uniqV.size(); } vector zip(const vector &V) { vector ret(V.size()); for (int i = 0; i < V.size(); i++) { ret[i] = encode(V[i]); } return ret; } vector unzip(const vector &V) { vector ret(V.size()); for (int i = 0; i < V.size(); i++) { ret[i] = decode(V[i]); } return ret; } int size() { return sz; } int encode(T x) { auto it = lower_bound(uniqV.begin(), uniqV.end(), x); return it - uniqV.begin(); } T decode(int x) { if (x < 0 or x >= uniqV.size()) return -1; // xが範囲外の場合 return uniqV[x]; } }; class UnionFind { public: UnionFind() = default; UnionFind(int N) : par(N), sz(N, 1) { iota(par.begin(), par.end(), 0); } int root(int x) { if (par[x] == x) return x; return (par[x] = root(par[x])); } bool unite(int x, int y) { int rx = root(x); int ry = root(y); if (rx == ry) return false; if (sz[rx] < sz[ry]) swap(rx, ry); sz[rx] += sz[ry]; par[ry] = rx; return true; } bool issame(int x, int y) { return (root(x) == root(y)); } int size(int x) { return sz[root(x)]; } vector> groups(int N) { vector> G(N); for (int x = 0; x < N; x++) { G[root(x)].push_back(x); } G.erase( remove_if(G.begin(), G.end(), [&](const vector& V) { return V.empty(); }), G.end()); return G; } private: vector par, sz; }; template struct BIT { int N; // 要素数 vector bit[2]; // データの格納先 BIT(int N_, int x = 0) { N = N_ + 1; bit[0].assign(N, 0); bit[1].assign(N, 0); if (x != 0) { for (int i = 0; i < N; i++) add(i, x); } } BIT(const vector &A) { N = A.size() + 1; bit[0].assign(N, 0); bit[1].assign(N, 0); for (int i = 0; i < (int)A.size(); i++) add(i, A[i]); } void add_sub(int p, int i, T x) { while (i < N) { bit[p][i] += x; i += (i & -i); } } void add(int l, int r, T x) { add_sub(0, l + 1, -x * l); add_sub(0, r + 1, x * r); add_sub(1, l + 1, x); add_sub(1, r + 1, -x); } void add(int i, T x) { add(i, i + 1, x); } T sum_sub(int p, int i) { T ret = 0; while (i > 0) { ret += bit[p][i]; i -= (i & -i); } return ret; } T sum(int i) { return sum_sub(0, i) + sum_sub(1, i) * i; } T sum(int l, int r) { return sum(r) - sum(l); } T get(int i) { return sum(i, i + 1); } void set(int i, T x) { T s = get(i); add(i, -s + x); } }; template class Modint { public: int val = 0; Modint(int x = 0) { while (x < 0) x += mod; val = x % mod; } Modint(const Modint &r) { val = r.val; } Modint operator -() { return Modint(-val); } // 単項 Modint operator +(const Modint &r) { return Modint(*this) += r; } Modint operator +(const int &q) { Modint r(q); return Modint(*this) += r; } Modint operator -(const Modint &r) { return Modint(*this) -= r; } Modint operator -(const int &q) { Modint r(q); return Modint(*this) -= r; } Modint operator *(const Modint &r) { return Modint(*this) *= r; } Modint operator *(const int &q) { Modint r(q); return Modint(*this) *= r; } Modint operator /(const Modint &r) { return Modint(*this) /= r; } Modint operator /(const int &q) { Modint r(q); return Modint(*this) /= r; } Modint& operator ++() { val++; if (val >= mod) val -= mod; return *this; } // 前置 Modint operator ++(signed) { ++*this; return *this; } // 後置 Modint& operator --() { val--; if (val < 0) val += mod; return *this; } Modint operator --(signed) { --*this; return *this; } Modint &operator +=(const Modint &r) { val += r.val; if (val >= mod) val -= mod; return *this; } Modint &operator +=(const int &q) { Modint r(q); val += r.val; if (val >= mod) val -= mod; return *this; } Modint &operator -=(const Modint &r) { if (val < r.val) val += mod; val -= r.val; return *this; } Modint &operator -=(const int &q) { Modint r(q); if (val < r.val) val += mod; val -= r.val; return *this; } Modint &operator *=(const Modint &r) { val = val * r.val % mod; return *this; } Modint &operator *=(const int &q) { Modint r(q); val = val * r.val % mod; return *this; } Modint &operator /=(const Modint &r) { int a = r.val, b = mod, u = 1, v = 0; while (b) {int t = a / b; a -= t * b; swap(a, b); u -= t * v; swap(u, v);} val = val * u % mod; if (val < 0) val += mod; return *this; } Modint &operator /=(const int &q) { Modint r(q); int a = r.val, b = mod, u = 1, v = 0; while (b) {int t = a / b; a -= t * b; swap(a, b); u -= t * v; swap(u, v);} val = val * u % mod; if (val < 0) val += mod; return *this; } bool operator ==(const Modint& r) { return this -> val == r.val; } bool operator <(const Modint& r) { return this -> val < r.val; } bool operator >(const Modint& r) { return this -> val > r.val; } bool operator !=(const Modint& r) { return this -> val != r.val; } friend istream &operator >>(istream &is, Modint& x) { int t; is >> t; x = t; return (is); } friend ostream &operator <<(ostream &os, const Modint& x) { return os << x.val; } }; using mint = Modint; mint modpow(const mint &x, int n) { if (n < 0) return (mint)1 / modpow(x, -n); // 未verify assert(n >= 0); if (n == 0) return 1; mint t = modpow(x, n / 2); t = t * t; if (n & 1) t = t * x; return t; } int modpow(__int128_t x, int n, int mod) { if (n == 0 && mod == 1) return 0; assert(n >= 0 && mod > 0); // TODO: n <= -1 __int128_t ret = 1; while (n > 0) { if (n % 2 == 1) ret = ret * x % mod; x = x * x % mod; n /= 2; } return ret; } // int modinv(__int128_t x, int mod) { // // assert(mod > 0); // // assert(x > 0); // if (x == 1 or x == 0) return 1; // return mod - modinv(mod % x, mod) * (mod / x) % mod; // } vector _fac, _finv, _inv; void COMinit(int N) { _fac.resize(N + 1); _finv.resize(N + 1); _inv.resize(N + 1); _fac[0] = _fac[1] = 1; _finv[0] = _finv[1] = 1; _inv[1] = 1; for (int i = 2; i <= N; i++) { _fac[i] = _fac[i-1] * mint(i); _inv[i] = -_inv[MOD % i] * mint(MOD / i); _finv[i] = _finv[i - 1] * _inv[i]; } } mint FAC(int N) { if (N < 0) return 0; return _fac[N]; } mint FACinv(int N) { if (N < 0) return 0; return _finv[N]; } mint COM(int N, int K) { if (N < K) return 0; if (N < 0 or K < 0) return 0; return _fac[N] * _finv[K] * _finv[N - K]; } mint COMinv(int N, int K) { if (N < K) return 0; if (N < 0 or K < 0) return 0; return _finv[N] * _fac[K] * _fac[N - K]; } mint MCOM(const vector &V) { int N = 0; for (int i = 0; i < V.size(); i++) N += V[i]; mint ret = _fac[N]; for (int i = 0; i < V.size(); i++) ret *= _finv[V[i]]; return ret; } mint PERM(int N, int K) { if (N < K) return 0; if (N < 0 or K < 0) return 0; return _fac[N] * _finv[N - K]; } mint NHK(int N, int K) { // initのサイズに注意 if (N == 0 && K == 0) return 1; return COM(N + K - 1, K); } #pragma endregion template class rangetree { int n; using Pt = pair; vector _pts; vector> _range2yxs; vector> bit; // 乗せたいBITを書く void _set(int v, Pt p, S val) { auto i = distance( _range2yxs[v].begin(), lower_bound(_range2yxs[v].begin(), _range2yxs[v].end(), Pt{p.second, p.first})); bit[v].add(i, -bit[v].sum(i, i + 1) + val); } void _add(int v, Pt p, S val) { auto i = distance( _range2yxs[v].begin(), lower_bound(_range2yxs[v].begin(), _range2yxs[v].end(), Pt{p.second, p.first})); bit[v].add(i, val); } S _prod(int v, Coordinate yl, Coordinate yr) { auto comp = [&](const Pt &l, const Pt &r) { return l.first < r.first; }; int il = distance( _range2yxs[v].begin(), lower_bound(_range2yxs[v].begin(), _range2yxs[v].end(), Pt{yl, yl}, comp)); int ir = distance( _range2yxs[v].begin(), lower_bound(_range2yxs[v].begin(), _range2yxs[v].end(), Pt{yr, yr}, comp)); return bit[v].sum(il, ir); } public: rangetree() = default; void add_point(Coordinate x, Coordinate y) noexcept { _pts.emplace_back(x, y); } void build() { sort(_pts.begin(), _pts.end()); _pts.erase(unique(_pts.begin(), _pts.end()), _pts.end()); n = _pts.size(); _range2yxs.resize(n * 2); for (int i = 0; i < n; i++) _range2yxs[n + i] = {{_pts[i].second, _pts[i].first}}; for (int i = n - 1; i > 0; i--) { auto &lch = _range2yxs[i * 2]; auto &rch = _range2yxs[i * 2 + 1]; merge( lch.begin(), lch.end(), rch.begin(), rch.end(), back_inserter(_range2yxs[i])); _range2yxs[i].erase( unique(_range2yxs[i].begin(), _range2yxs[i].end()), _range2yxs[i].end()); } for (const auto &v : _range2yxs) bit.emplace_back(v.size()); } void set(Coordinate x, Coordinate y, S val) { int i = distance(_pts.begin(), lower_bound(_pts.begin(), _pts.end(), Pt{x, y})); assert(i < n && _pts[i] == make_pair(x, y)); for (i += n; i; i >>= 1) _set(i, {x, y}, val); } void add(Coordinate x, Coordinate y, S val) { int i = distance(_pts.begin(), lower_bound(_pts.begin(), _pts.end(), Pt{x, y})); assert(i < n && _pts[i] == make_pair(x, y)); for (i += n; i; i >>= 1) _add(i, {x, y}, val); } S prod(Coordinate xl, Coordinate xr, Coordinate yl, Coordinate yr) { auto comp = [](const Pt &l, const Pt &r) { return l.first < r.first; }; int l = n + distance(_pts.begin(), lower_bound(_pts.begin(), _pts.end(), Pt{xl, yr}, comp)); int r = n + distance(_pts.begin(), lower_bound(_pts.begin(), _pts.end(), Pt{xr, yr}, comp)); S ret = 0; while (l < r) { if (l & 1) ret += _prod(l++, yl, yr); if (r & 1) ret += _prod(--r, yl, yr); l >>= 1, r >>= 1; } return ret; } S get(Coordinate x, Coordinate y) const { return prod(x, x + 1, y, y + 1); } }; using S = modint1000000007; rangetree RT; vector A, dp, L, X; vector cnt; signed main() { int N; cin >> N; A.resize(N); for (int i = 0; i < N; i++) cin >> A[i]; Compress C(A); A = C.zip(A); int len = 0; dp.assign(N + 1, N + 1); L.resize(N + 1); X.resize(N); cnt.resize(N + 1); for (int i = 0; i < N; i++) { int x = lower_bound(L.begin(), L.begin() + len, A[i]) - L.begin(); X[i] = x; dp[i] = x + 1; L[x] = A[i]; // 長さxの最後尾の要素の最小値はA[i] if (dp[i] > len) len++; RT.add_point(A[i], dp[i]); } RT.build(); dp.assign(N + 1, N + 1); L.assign(N + 1, 0); len = 0; for (int i = 0; i < N; i++) { int x = X[i]; dp[i] = x + 1; L[x] = A[i]; // 長さxの最後尾の要素の最小値はA[i] if (dp[i] > len) len++; if (dp[i] > 0) { // 半開 x 半開 // x1, x2, y1, y2 cnt[i] += RT.prod(0, A[i], dp[i] - 1, dp[i]); } if (cnt[i].val() == 0) cnt[i] = 1; RT.add(A[i], dp[i], cnt[i]); } S ans = 0; for (int i = 0; i < N; i++) { if (dp[i] == len) ans += cnt[i]; } cout << ans.val() << endl; }