#include #pragma GCC optimize("Ofast") #pragma GCC optimize("unroll-loops") using namespace std; using std::cout; using std::cin; using std::endl; using ll=long long; using ld=long double; const ll ILL=2167167167167167167; const int INF=2100000000; const int mod=998244353; #define rep(i,a,b) for (int i=(int)(a);i<(int)(b);i++) #define all(p) p.begin(),p.end() template using _pq = priority_queue, greater>; template ll LB(vector &v,T a){return lower_bound(v.begin(),v.end(),a)-v.begin();} template ll UB(vector &v,T a){return upper_bound(v.begin(),v.end(),a)-v.begin();} template bool chmin(T &a,const T &b){if(a>b){a=b;return 1;}else return 0;} template bool chmax(T &a,const T &b){if(a void So(vector &v) {sort(v.begin(),v.end());} template void Sore(vector &v) {sort(v.begin(),v.end(),[](T x,T y){return x>y;});} void yneos(bool a){if(a) cout<<"Yes\n"; else cout<<"No\n";} template void vec_out(vector &p){for(int i=0;i<(int)(p.size());i++){if(i) cout<<" ";cout< T vec_min(vector &a){assert(!a.empty());T ans=a[0];for(auto &x:a) chmin(ans,x);return ans;} template T vec_max(vector &a){assert(!a.empty());T ans=a[0];for(auto &x:a) chmax(ans,x);return ans;} template T vec_sum(vector &a){assert(!a.empty());T ans=a[0]-a[0];for(auto &x:a) ans+=x;return ans;} int pop_count(long long a){int res=0;while(a){res+=(a&1),a>>=1;}return res;} ll jyo(ll x,ll y,ll z){ ll H=y; //ここから ll a=1,b=(x%z+z)%z,c=1; while(H>0){ a*=2; if(H%a!=0){ H-=a/2; c*=b; c%=z; } b*=b; b%=z; } //ここまで return c; } namespace po167{ struct combination{ int upper; int MOD; std::vector fact; std::vector rev; std::vector fact_rev; combination(int max,long long mod):upper(max),MOD(mod),fact(max+1),rev(max+1),fact_rev(max+1){ for(long long i=0;i<=max;i++){ if(i<2){ fact[i]=1; fact_rev[i]=1; rev[i]=1; continue; } fact[i]=(fact[i-1]*i)%mod; rev[i]=mod-((mod/i)*rev[mod%i])%mod; fact_rev[i]=(fact_rev[i-1]*rev[i])%mod; } } long long Comb(int x,int y){ assert(upper>=x); if (x=x); if (x= 2 // im = ceil(2^64 / m) // -> im * m = 2^64 + r (0 <= r < m) // let z = a*b = c*m + d (0 <= c, d < m) // a*b * im = (c*m + d) * im = c*(im*m) + d*im = c*2^64 + c*r + d*im // c*r + d*im < m * m + m * im < m * m + 2^64 + m <= 2^64 + m * (m + 1) < 2^64 * 2 // ((ab * im) >> 64) == c or c + 1 unsigned long long z = a; z *= b; #ifdef _MSC_VER unsigned long long x; _umul128(z, im, &x); #else unsigned long long x = (unsigned long long)(((unsigned __int128)(z)*im) >> 64); #endif unsigned int v = (unsigned int)(z - x * _m); if (_m <= v) v += _m; return v; } }; // @param n `0 <= n` // @param m `1 <= m` // @return `(x ** n) % m` constexpr long long pow_mod_constexpr(long long x, long long n, int m) { if (m == 1) return 0; unsigned int _m = (unsigned int)(m); unsigned long long r = 1; unsigned long long y = safe_mod(x, m); while (n) { if (n & 1) r = (r * y) % _m; y = (y * y) % _m; n >>= 1; } return r; } // Reference: // M. Forisek and J. Jancina, // Fast Primality Testing for Integers That Fit into a Machine Word // @param n `0 <= n` constexpr bool is_prime_constexpr(int n) { if (n <= 1) return false; if (n == 2 || n == 7 || n == 61) return true; if (n % 2 == 0) return false; long long d = n - 1; while (d % 2 == 0) d /= 2; constexpr long long bases[3] = {2, 7, 61}; for (long long a : bases) { long long t = d; long long y = pow_mod_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 is_prime = is_prime_constexpr(n); // @param b `1 <= b` // @return pair(g, x) s.t. g = gcd(a, b), xa = g (mod b), 0 <= x < b/g constexpr std::pair inv_gcd(long long a, long long b) { a = safe_mod(a, b); if (a == 0) return {b, 0}; // Contracts: // [1] s - m0 * a = 0 (mod b) // [2] t - m1 * a = 0 (mod b) // [3] s * |m1| + t * |m0| <= b long long s = b, t = a; long long m0 = 0, m1 = 1; while (t) { long long u = s / t; s -= t * u; m0 -= m1 * u; // |m1 * u| <= |m1| * s <= b // [3]: // (s - t * u) * |m1| + t * |m0 - m1 * u| // <= s * |m1| - t * u * |m1| + t * (|m0| + |m1| * u) // = s * |m1| + t * |m0| <= b auto tmp = s; s = t; t = tmp; tmp = m0; m0 = m1; m1 = tmp; } // by [3]: |m0| <= b/g // by g != b: |m0| < b/g if (m0 < 0) m0 += b / s; return {s, m0}; } // Compile time primitive root // @param m must be prime // @return primitive root (and minimum in now) constexpr int primitive_root_constexpr(int m) { if (m == 2) return 1; if (m == 167772161) return 3; if (m == 469762049) return 3; if (m == 754974721) return 11; if (m == 998244353) return 3; int divs[20] = {}; divs[0] = 2; int cnt = 1; int x = (m - 1) / 2; while (x % 2 == 0) x /= 2; for (int i = 3; (long long)(i)*i <= x; i += 2) { if (x % i == 0) { divs[cnt++] = i; while (x % i == 0) { x /= i; } } } if (x > 1) { divs[cnt++] = x; } for (int g = 2;; g++) { bool ok = true; for (int i = 0; i < cnt; i++) { if (pow_mod_constexpr(g, (m - 1) / divs[i], m) == 1) { ok = false; break; } } if (ok) return g; } } template constexpr int primitive_root = primitive_root_constexpr(m); } // namespace internal namespace internal { #ifndef _MSC_VER template using is_signed_int128 = typename std::conditional::value || std::is_same::value, std::true_type, std::false_type>::type; template using is_unsigned_int128 = typename std::conditional::value || std::is_same::value, std::true_type, std::false_type>::type; template using make_unsigned_int128 = typename std::conditional::value, __uint128_t, unsigned __int128>; template using is_integral = typename std::conditional::value || is_signed_int128::value || is_unsigned_int128::value, std::true_type, std::false_type>::type; template using is_signed_int = typename std::conditional<(is_integral::value && std::is_signed::value) || is_signed_int128::value, std::true_type, std::false_type>::type; template using is_unsigned_int = typename std::conditional<(is_integral::value && std::is_unsigned::value) || is_unsigned_int128::value, std::true_type, std::false_type>::type; template using to_unsigned = typename std::conditional< is_signed_int128::value, make_unsigned_int128, typename std::conditional::value, std::make_unsigned, std::common_type>::type>::type; #else template using is_integral = typename std::is_integral; template using is_signed_int = typename std::conditional::value && std::is_signed::value, std::true_type, std::false_type>::type; template using is_unsigned_int = typename std::conditional::value && std::is_unsigned::value, std::true_type, std::false_type>::type; template using to_unsigned = typename std::conditional::value, std::make_unsigned, std::common_type>::type; #endif template using is_signed_int_t = std::enable_if_t::value>; template using is_unsigned_int_t = std::enable_if_t::value>; template using to_unsigned_t = typename to_unsigned::type; } // namespace internal namespace internal { struct modint_base {}; struct static_modint_base : modint_base {}; template using is_modint = std::is_base_of; template using is_modint_t = std::enable_if_t::value>; } // namespace internal template * = nullptr> struct static_modint : internal::static_modint_base { using mint = static_modint; public: static constexpr int mod() { return m; } static mint raw(int v) { mint x; x._v = v; return x; } static_modint() : _v(0) {} template * = nullptr> static_modint(T v) { long long x = (long long)(v % (long long)(umod())); if (x < 0) x += umod(); _v = (unsigned int)(x); } template * = nullptr> static_modint(T v) { _v = (unsigned int)(v % umod()); } static_modint(bool v) { _v = ((unsigned int)(v) % umod()); } unsigned int val() const { return _v; } mint& operator++() { _v++; if (_v == umod()) _v = 0; return *this; } mint& operator--() { if (_v == 0) _v = umod(); _v--; return *this; } mint operator++(int) { mint result = *this; ++*this; return result; } mint operator--(int) { mint result = *this; --*this; return result; } mint& operator+=(const mint& rhs) { _v += rhs._v; if (_v >= umod()) _v -= umod(); return *this; } mint& operator-=(const mint& rhs) { _v -= rhs._v; if (_v >= umod()) _v += umod(); return *this; } mint& operator*=(const mint& rhs) { unsigned long long z = _v; z *= rhs._v; _v = (unsigned int)(z % umod()); return *this; } mint& operator/=(const mint& rhs) { return *this = *this * rhs.inv(); } mint operator+() const { return *this; } mint operator-() const { return mint() - *this; } mint pow(long long n) const { assert(0 <= n); mint x = *this, r = 1; while (n) { if (n & 1) r *= x; x *= x; n >>= 1; } return r; } mint inv() const { if (prime) { assert(_v); return pow(umod() - 2); } else { auto eg = internal::inv_gcd(_v, m); assert(eg.first == 1); return eg.second; } } 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; } private: unsigned int _v; static constexpr unsigned int umod() { return m; } static constexpr bool prime = internal::is_prime; }; template struct dynamic_modint : internal::modint_base { using mint = dynamic_modint; public: static int mod() { return (int)(bt.umod()); } static void set_mod(int m) { assert(1 <= m); bt = internal::barrett(m); } static mint raw(int v) { mint x; x._v = v; return x; } dynamic_modint() : _v(0) {} template * = nullptr> dynamic_modint(T v) { long long x = (long long)(v % (long long)(mod())); if (x < 0) x += mod(); _v = (unsigned int)(x); } template * = nullptr> dynamic_modint(T v) { _v = (unsigned int)(v % mod()); } dynamic_modint(bool v) { _v = ((unsigned int)(v) % mod()); } unsigned int val() const { return _v; } mint& operator++() { _v++; if (_v == umod()) _v = 0; return *this; } mint& operator--() { if (_v == 0) _v = umod(); _v--; return *this; } mint operator++(int) { mint result = *this; ++*this; return result; } mint operator--(int) { mint result = *this; --*this; return result; } mint& operator+=(const mint& rhs) { _v += rhs._v; if (_v >= umod()) _v -= umod(); return *this; } mint& operator-=(const mint& rhs) { _v += mod() - rhs._v; if (_v >= umod()) _v -= umod(); return *this; } mint& operator*=(const mint& rhs) { _v = bt.mul(_v, rhs._v); return *this; } mint& operator/=(const mint& rhs) { return *this = *this * rhs.inv(); } mint operator+() const { return *this; } mint operator-() const { return mint() - *this; } mint pow(long long n) const { assert(0 <= n); mint x = *this, r = 1; while (n) { if (n & 1) r *= x; x *= x; n >>= 1; } return r; } mint inv() const { auto eg = internal::inv_gcd(_v, mod()); assert(eg.first == 1); return eg.second; } 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; } private: unsigned int _v; static internal::barrett bt; static unsigned int umod() { return bt.umod(); } }; template internal::barrett dynamic_modint::bt = 998244353; using modint998244353 = static_modint<998244353>; using modint1000000007 = static_modint<1000000007>; using modint = dynamic_modint<-1>; namespace internal { template using is_static_modint = std::is_base_of; template using is_static_modint_t = std::enable_if_t::value>; template struct is_dynamic_modint : public std::false_type {}; template struct is_dynamic_modint> : public std::true_type {}; template using is_dynamic_modint_t = std::enable_if_t::value>; } // namespace internal namespace internal { template * = nullptr> void butterfly(std::vector& a) { static constexpr int g = internal::primitive_root; int n = int(a.size()); int h = internal::ceil_pow2(n); static bool first = true; static mint sum_e[30]; // sum_e[i] = ies[0] * ... * ies[i - 1] * es[i] if (first) { first = false; mint es[30], ies[30]; // es[i]^(2^(2+i)) == 1 int cnt2 = bsf(mint::mod() - 1); mint e = mint(g).pow((mint::mod() - 1) >> cnt2), ie = e.inv(); for (int i = cnt2; i >= 2; i--) { // e^(2^i) == 1 es[i - 2] = e; ies[i - 2] = ie; e *= e; ie *= ie; } mint now = 1; for (int i = 0; i <= cnt2 - 2; i++) { sum_e[i] = es[i] * now; now *= ies[i]; } } for (int ph = 1; ph <= h; ph++) { int w = 1 << (ph - 1), p = 1 << (h - ph); mint now = 1; for (int s = 0; s < w; s++) { int offset = s << (h - ph + 1); for (int i = 0; i < p; i++) { auto l = a[i + offset]; auto r = a[i + offset + p] * now; a[i + offset] = l + r; a[i + offset + p] = l - r; } now *= sum_e[bsf(~(unsigned int)(s))]; } } } template * = nullptr> void butterfly_inv(std::vector& a) { static constexpr int g = internal::primitive_root; int n = int(a.size()); int h = internal::ceil_pow2(n); static bool first = true; static mint sum_ie[30]; // sum_ie[i] = es[0] * ... * es[i - 1] * ies[i] if (first) { first = false; mint es[30], ies[30]; // es[i]^(2^(2+i)) == 1 int cnt2 = bsf(mint::mod() - 1); mint e = mint(g).pow((mint::mod() - 1) >> cnt2), ie = e.inv(); for (int i = cnt2; i >= 2; i--) { // e^(2^i) == 1 es[i - 2] = e; ies[i - 2] = ie; e *= e; ie *= ie; } mint now = 1; for (int i = 0; i <= cnt2 - 2; i++) { sum_ie[i] = ies[i] * now; now *= es[i]; } } for (int ph = h; ph >= 1; ph--) { int w = 1 << (ph - 1), p = 1 << (h - ph); mint inow = 1; for (int s = 0; s < w; s++) { int offset = s << (h - ph + 1); for (int i = 0; i < p; i++) { auto l = a[i + offset]; auto r = a[i + offset + p]; a[i + offset] = l + r; a[i + offset + p] = (unsigned long long)(mint::mod() + l.val() - r.val()) * inow.val(); } inow *= sum_ie[bsf(~(unsigned int)(s))]; } } } } // namespace internal template * = nullptr> std::vector convolution(std::vector a, std::vector b) { int n = int(a.size()), m = int(b.size()); if (!n || !m) return {}; if (std::min(n, m) <= 60) { if (n < m) { std::swap(n, m); std::swap(a, b); } std::vector ans(n + m - 1); for (int i = 0; i < n; i++) { for (int j = 0; j < m; j++) { ans[i + j] += a[i] * b[j]; } } return ans; } int z = 1 << internal::ceil_pow2(n + m - 1); a.resize(z); internal::butterfly(a); b.resize(z); internal::butterfly(b); for (int i = 0; i < z; i++) { a[i] *= b[i]; } internal::butterfly_inv(a); a.resize(n + m - 1); mint iz = mint(z).inv(); for (int i = 0; i < n + m - 1; i++) a[i] *= iz; return a; } template ::value>* = nullptr> std::vector convolution(const std::vector& a, const std::vector& b) { int n = int(a.size()), m = int(b.size()); if (!n || !m) return {}; using mint = static_modint; std::vector a2(n), b2(m); for (int i = 0; i < n; i++) { a2[i] = mint(a[i]); } for (int i = 0; i < m; i++) { b2[i] = mint(b[i]); } auto c2 = convolution(move(a2), move(b2)); std::vector c(n + m - 1); for (int i = 0; i < n + m - 1; i++) { c[i] = c2[i].val(); } return c; } std::vector convolution_ll(const std::vector& a, const std::vector& b) { int n = int(a.size()), m = int(b.size()); if (!n || !m) return {}; static constexpr unsigned long long MOD1 = 754974721; // 2^24 static constexpr unsigned long long MOD2 = 167772161; // 2^25 static constexpr unsigned long long MOD3 = 469762049; // 2^26 static constexpr unsigned long long M2M3 = MOD2 * MOD3; static constexpr unsigned long long M1M3 = MOD1 * MOD3; static constexpr unsigned long long M1M2 = MOD1 * MOD2; static constexpr unsigned long long M1M2M3 = MOD1 * MOD2 * MOD3; static constexpr unsigned long long i1 = internal::inv_gcd(MOD2 * MOD3, MOD1).second; static constexpr unsigned long long i2 = internal::inv_gcd(MOD1 * MOD3, MOD2).second; static constexpr unsigned long long i3 = internal::inv_gcd(MOD1 * MOD2, MOD3).second; auto c1 = convolution(a, b); auto c2 = convolution(a, b); auto c3 = convolution(a, b); std::vector c(n + m - 1); for (int i = 0; i < n + m - 1; i++) { unsigned long long x = 0; x += (c1[i] * i1) % MOD1 * M2M3; x += (c2[i] * i2) % MOD2 * M1M3; x += (c3[i] * i3) % MOD3 * M1M2; // B = 2^63, -B <= x, r(real value) < B // (x, x - M, x - 2M, or x - 3M) = r (mod 2B) // r = c1[i] (mod MOD1) // focus on MOD1 // r = x, x - M', x - 2M', x - 3M' (M' = M % 2^64) (mod 2B) // r = x, // x - M' + (0 or 2B), // x - 2M' + (0, 2B or 4B), // x - 3M' + (0, 2B, 4B or 6B) (without mod!) // (r - x) = 0, (0) // - M' + (0 or 2B), (1) // -2M' + (0 or 2B or 4B), (2) // -3M' + (0 or 2B or 4B or 6B) (3) (mod MOD1) // we checked that // ((1) mod MOD1) mod 5 = 2 // ((2) mod MOD1) mod 5 = 3 // ((3) mod MOD1) mod 5 = 4 long long diff = c1[i] - internal::safe_mod((long long)(x), (long long)(MOD1)); if (diff < 0) diff += MOD1; static constexpr unsigned long long offset[5] = { 0, 0, M1M2M3, 2 * M1M2M3, 3 * M1M2M3}; x -= offset[diff % 5]; c[i] = x; } return c; } } // namespace atcoder using namespace atcoder; //参考 https://nyaannyaan.github.io/library/fps/formal-power-series.hpp.html namespace po167{ long long rev(long long a,long long MOD){ long long D=1,C=MOD-2; while(C){ if(C&1) D=(D*a)%MOD; C>>=1; a=(a*a)%MOD; } return D; } template std::vector add_Polynomial(std::vector &p,std::vector &q){ std::vector r(std::max(p.size(),q.size())); for(int i=0;i<(int)r.size();i++){ if((int)p.size()>i) r[i]=p[i]; if((int)q.size()>i) r[i]=(r[i]+q[i])%mod; } return r; } template std::vector sub_Polynomial(std::vector &p,std::vector &q){ std::vector r(std::max(p.size(),q.size())); for(int i=0;i<(int)r.size();i++){ if((int)p.size()>i) r[i]=p[i]; if((int)q.size()>i) r[i]=(r[i]-q[i]); if(r[i]<0) r[i]=(r[i]%mod+mod)%mod; } return r; } template long long substitution_Polynomial(std::vector &p,long long x){ long long ans=0; long long D=1; for(int i=0;i std::vector differential_Polynomial(std::vector &p){ int N=p.size(); std::vector r(N); for(int i=1;i std::vector Integral_Polynomial(std::vector &p){ int N=p.size(); std::vector r(1+N); std::vector rev(N+1,1); for(int i=0;i1){ rev[i+1]=(mod-((mod/(i+1))*rev[mod%(i+1)])%mod)%mod; } r[i+1]=(rev[i+1]*p[i])%mod; } return r; } template std::vector slice_vec(std::vector &p,int S){ if(S>=(int)(p.size())) return p; std::vector r(S); for(int i=0;i std::vector inv_FPS(std::vector &p,int L){ int N=p.size(); assert(0 q={1},tmp,tmp2; long long D=p[0]; long long C=mod-2; while(C){ if(C&1){ q[0]=(q[0]*D)%mod; } C>>=1; D=(D*D)%mod; } int S=1; while(S(tmp,convolution(q,q)); for(int i=0;i ans(S); for(int i=0;i std::vector log_FPS(int N,int L,std::vector &p){ assert(p[0]==1); auto tmp=convolution(differential_Polynomial(p),inv_FPS(p,L)); auto tmp3=Integral_Polynomial(tmp); return slice_vec(tmp3,L); } // return e^{f(x)} template std::vector exp_FPS(int N,int L,std::vector &p){ assert((int)p.size()==N); assert(0 q={1},tmp,tmp2,tmp3; int S=1; while(S(S/2,S,q); tmp3=sub_Polynomial(tmp,tmp2); tmp3[0]++; tmp=convolution(q,tmp3); for(int i=0;i ans(S); for(int i=0;i zero_cut(std::vector &p){ int ind=0; for(int i=0;i<(int)(p.size());i++){ if(p[i]!=0) ind=i; } return slice_vec(p,ind+1); } //return {a,b} (p=aq+b) //https://judge.yosupo.jp/submission/79020 template std::pair,std::vector> div_FPS(std::vector &p,std::vector &q){ int N=p.size(),M=q.size(); if(N(f,inv_FPS(g,N-M+1)); auto ans1=slice_vec(tmp,N-M+1); std::reverse(ans1.begin(),ans1.end()); tmp=convolution(ans1,q); std::vector ans2(M-1); for(int i=0;i std::vector Multipoint_Evaluation(std::vector f,std::vectorp){ int M=p.size(); if(M==0){ return {}; } std::vector size={M}; int ind=0; while(size[ind]!=1){ size.push_back((size[ind]+1)/2); ind++; } ind++; std::vector>> divisor(ind),remain(ind); for(int i=0;i(divisor[i-1][j*2],divisor[i-1][j*2+1]); }else{ divisor[i][j]=divisor[i-1][size[i-1]-1]; } } } } for(int i=ind-1;i>=0;i--){ remain[i].resize(size[i]); if(i==ind-1){ remain[i][0]=div_FPS(f,divisor[ind-1][0]).second; }else{ for(int j=0;j ans(M); for(int i=0;i std::vector multiplication_FPS(std::vector> &p){ std::queue> pq; int N=p.size(); for(int i=0;i(l,r)); } return pq.front(); } struct frac_fps{ std::vector ch; std::vector mo; }; template frac_fps add_frac_fps(frac_fps &l,frac_fps &r){ auto tmp1=convolution(l.ch,r.mo); auto tmp2=convolution(l.mo,r.ch); return {add_Polynomial(tmp1,tmp2),convolution(l.mo,r.mo)}; } template std::vector Polynomial_Interpolation(std::vector &x,std::vector &y){ int N=x.size(); assert(x.size()==y.size()); std::vector> p(N); for(int i=0;i(p); auto div=differential_Polynomial(tmp1); auto val=Multipoint_Evaluation(div,x); std::queue q; for(int i=0;i(l,r)); } long long D=1; auto ans=q.front().ch; for(int i=0;i T mod_add(const T a, const T b, const T mod){ return (a + b) % mod; } template T mod_mul(const T a, const T b, const T mod){ return a * b % mod; } template T mod_inv(T a, T mod){ T u[] = {a, 1, 0}, v[] = {mod, 0, 1}, t; while(*v){ t = *u / *v; swap(u[0] -= t * v[0], v[0]); swap(u[1] -= t * v[1], v[1]); swap(u[2] -= t * v[2], v[2]); } u[1] %= mod; return (u[1] < 0) ? (u[1] + mod) : u[1]; } template T garner(const vector& a, vector p, const T mod){ const unsigned int sz = a.size(); vector kp(sz + 1, 0), rmult(sz + 1, 1); p.push_back(mod); for(unsigned int i = 0; i < sz; ++i){ T x = mod_mul(a[i] - kp[i], mod_inv(rmult[i], p[i]), p[i]); x = (x < 0) ? (x + p[i]) : x; for(unsigned int j = i + 1; j < sz + 1; ++j){ kp[j] = mod_add(kp[j], rmult[j] * x, p[j]); rmult[j] = mod_mul(rmult[j], p[i], p[j]); } } return kp[sz]; } const long long _mod0=754974721; const long long _mod1=167772161; const long long _mod2=469762049; std::vector _MOD={_mod0,_mod1,_mod2}; std::vector convolution_any_mod(std::vector a,std::vector b,long long pmod){ for(auto &x:a) x=(x%pmod+pmod)%pmod; for(auto &x:b) x=(x%pmod+pmod)%pmod; std::vector> res(3); res[0]=convolution<_mod0>(a,b); res[1]=convolution<_mod1>(a,b); res[2]=convolution<_mod2>(a,b); for(int i=0;i<(int)res[0].size();i++){ std::vector q(3); for(int j=0;j<3;j++) q[j]=res[j][i]; res[0][i]=garner(q,_MOD,pmod); } return res[0]; } //retrun [x^ind](a(x)/b(x)) template long long boston_mori(std::vector a,std::vector b,long long ind){ assert(ind>=0); while(ind){ std::vector n_a,n_b,c=b; for(int i=0;i<(int)(c.size());i++) if(i&1) c[i]*=-1; a=convolution(c,a); b=convolution(c,b); for(int i=0;i<(int)(b.size());i++) if((i+1)&1) n_b.push_back(b[i]); for(int i=0;i<(int)(a.size());i++) if((i+1+ind)&1) n_a.push_back(a[i]); std::swap(a,n_a); std::swap(b,n_b); ind>>=1; } return (mod+(a[0]*rev(b[0],mod))%mod)%mod; } } void solve(); // oddloop int main() { ios::sync_with_stdio(false); cin.tie(nullptr); int t=1; //cin>>t; rep(i,0,t) solve(); } void solve(){ ll H,W,N,K; cin>>H>>W>>N>>K; ll S=(H-K+1)*(W-K+1)%mod; ll Sr=jyo(S,mod-2,mod); ll ans=0; combination table(N+10,mod); /* auto f=[&](ll a)->ll { a%=mod; return (1-jyo((S-a)*Sr%mod,N,mod))%mod; }; auto h=[&](ll a,ll b)->ll { return min(b-K+1,a+1)-max(0ll,a-K+1); };*/ auto e=[&](ll a)->vector { vector X(N+10),Y(N+10); ll tmp=1; a+=1; rep(i,0,N+10){ tmp=tmp*a%mod; Y[i]=table.fact_rev[i+1]; X[i]=Y[i]*tmp%mod; } X=convolution(X,po167::inv_FPS(Y,N+10)); X.resize(N+1); rep(i,0,N+1) X[i]=X[i]*table.fact[i]%mod; X[0]--; return X; }; auto g=[&](ll a)->vector { vector res(N+1); if(a<2*K){ res=e(a-K); //vec_out(res); ll tmp=1; rep(i,0,N+1){ res[i]=res[i]*2ll%mod; res[i]=(res[i]+tmp*(2*K-a))%mod; tmp=tmp*(a-K+1)%mod; } }else{ res=e(K); ll tmp=1; rep(i,0,N+1){ res[i]=res[i]*2ll%mod; res[i]=(res[i]+tmp*(a-2*K))%mod; tmp=tmp*K%mod; } } return res; }; auto A=g(H),B=g(W); vector q(N+1,1); rep(i,0,N) q[i+1]=q[i]*S%mod; rep(i,0,N+1){ ll tmp=1; if(i&1) tmp*=-1; tmp=tmp*(A[i]*B[i])%mod; //cout<