#include using namespace std; #define MD 1000000007 void *wmem; template void malloc1d(T **arr, int x, void **mem = &wmem){ (*arr)=(T*)(*mem); (*mem)=((*arr)+x); } struct mint{ static unsigned R, RR, Rinv, W, md, mdninv; unsigned val; mint(){ } mint(int a){ val = mulR(a); } mint(unsigned a){ val = mulR(a); } mint(long long a){ val = mulR(a); } mint(unsigned long long a){ val = mulR(a); } int get_inv(long long a, int md){ long long e, s=md, t=a, u=1, v=0; while(s){ e=t/s; t-=e*s; u-=e*v; swap(t,s); swap(u,v); } if(u<0){ u+=md; } return u; } void setmod(unsigned m){ int i; unsigned t; W = 32; md = m; R = (1ULL << W) % md; RR = (unsigned long long)R*R % md; switch(m){ case 104857601: Rinv = 2560000; mdninv = 104857599; break; case 998244353: Rinv = 232013824; mdninv = 998244351; break; case 1000000007: Rinv = 518424770; mdninv = 2226617417U; break; case 1000000009: Rinv = 171601999; mdninv = 737024967; break; case 1004535809: Rinv = 234947584; mdninv = 1004535807; break; case 1007681537: Rinv = 236421376; mdninv = 1007681535; break; case 1012924417: Rinv = 238887936; mdninv = 1012924415; break; case 1045430273: Rinv = 254466304; mdninv = 1045430271; break; case 1051721729: Rinv = 257538304; mdninv = 1051721727; break; default: Rinv = get_inv(R, md); mdninv = 0; t = 0; for(i=0;i<(int)W;i++){ if(t%2==0){ t+=md; mdninv |= (1U<> W); if(t >= md){ t -= md; } return t; } unsigned reduce(unsigned long long T){ unsigned m=(unsigned)T * mdninv, t=(unsigned)((T + (unsigned long long)m*md) >> W); if(t >= md){ t -= md; } return t; } unsigned get(){ return reduce(val); } mint &operator+=(mint a){ val += a.val; if(val >= md){ val -= md; } return *this; } mint &operator-=(mint a){ if(val < a.val){ val = val + md - a.val; } else{ val -= a.val; } return *this; } mint &operator*=(mint a){ val = reduce((unsigned long long)val*a.val); return *this; } mint &operator/=(mint a){ return *this *= a.inverse(); } mint operator+(mint a){ return mint(*this)+=a; } mint operator-(mint a){ return mint(*this)-=a; } mint operator*(mint a){ return mint(*this)*=a; } mint operator/(mint a){ return mint(*this)/=a; } mint operator+(int a){ return mint(*this)+=mint(a); } mint operator-(int a){ return mint(*this)-=mint(a); } mint operator*(int a){ return mint(*this)*=mint(a); } mint operator/(int a){ return mint(*this)/=mint(a); } mint operator+(long long a){ return mint(*this)+=mint(a); } mint operator-(long long a){ return mint(*this)-=mint(a); } mint operator*(long long a){ return mint(*this)*=mint(a); } mint operator/(long long a){ return mint(*this)/=mint(a); } mint operator-(void){ mint res; if(val){ res.val=md-val; } else{ res.val=0; } return res; } operator bool(void){ return val!=0; } operator int(void){ return get(); } operator long long(void){ return get(); } mint inverse(){ int a = val, b = md, u = 1, v = 0, t; mint res; while(b){ t = a / b; a -= t * b; swap(a, b); u -= t * v; swap(u, v); } if(u < 0) u += md; res.val = (unsigned long long)u*RR % md; return res; } mint pw(unsigned long long b){ mint a(*this), res; res.val = R; while(b){ if(b&1) res *= a; b >>= 1; a *= a; } return res; } bool operator==(int a){return mulR(a)==val;} bool operator!=(int a){return mulR(a)!=val;} }; unsigned mint::md, mint::W, mint::R, mint::Rinv, mint::mdninv, mint::RR; mint operator+(int a, mint b){return mint(a)+=b; } mint operator-(int a, mint b){ return mint(a)-=b; } mint operator*(int a, mint b){ return mint(a)*=b; } mint operator/(int a, mint b){ return mint(a)/=b; } mint operator+(long long a, mint b){ return mint(a)+=b; } mint operator-(long long a, mint b){ return mint(a)-=b; } mint operator*(long long a, mint b){ return mint(a)*=b; } mint operator/(long long a, mint b){ return mint(a)/=b; } void rd(int &x){ int k, m=0; x=0; for(;;){ k = getchar_unlocked(); if(k=='-'){ m=1; break; } if('0'<=k&&k<='9'){ x=k-'0'; break; } } for(;;){ k = getchar_unlocked(); if(k<'0'||k>'9'){ break; } x=x*10+k-'0'; } if(m){ x=-x; } } void rd(mint &x){ int i; rd(i); x=i; } void wt_L(int x){ char f[10]; int m=0, s=0; if(x<0){ m=1; x=-x; } while(x){ f[s++]=x%10; x/=10; } if(!s){ f[s++]=0; } if(m){ putchar_unlocked('-'); } while(s--){ putchar_unlocked(f[s]+'0'); } } void wt_L(mint x){ int i; i = (int)x; wt_L(i); } struct combination_mint{ mint *fac, *ifac; void init(int n, void **mem = &wmem){ int i; malloc1d(&fac, n, mem); malloc1d(&ifac, n, mem); fac[0] = 1; for(i=1;i=0;i--){ ifac[i] = ifac[i+1] * (i+1); } } mint C(int a, int b){ if(b < 0 || b > a){ return 0; } return fac[a]*ifac[b]*ifac[a-b]; } mint P(int a, int b){ if(b < 0 || b > a){ return 0; } return fac[a]*ifac[a-b]; } mint H(int a, int b){ if(a==0 && b==0){ return 1; } if(a<=0 || b<0){ return 0; } return C(a+b-1, b); } } ; char memarr[64000000]; int main(){ combination_mint comb; int K, N, i, r, t; mint D, m, res; wmem = memarr; { mint x; x.setmod(MD); } comb.init(1000100); rd(N); rd(K); rd(D); t = (N-1) / (K-1); r = N - t * (K-1); if(D==1){ wt_L(r); putchar_unlocked('\n'); } else{ res = 0; m = 1; for(i=0;i