#include "bits/stdc++.h" using namespace std; #define FOR(i,j,k) for(int (i)=(j);(i)<(int)(k);++(i)) #define rep(i,j) FOR(i,0,j) #define each(x,y) for(auto &(x):(y)) #define mp make_pair #define mt make_tuple #define all(x) (x).begin(),(x).end() #define debug(x) cout<<#x<<": "<<(x)< pii; typedef vector vi; typedef vector vll; template class ModInt { public: ModInt() :value(0) {} ModInt(long long val) :value((int)(val<0 ? MOD + val%MOD : val%MOD)) { } ModInt& operator+=(ModInt that) { value = value + that.value; if (value >= MOD)value -= MOD; return *this; } ModInt& operator-=(ModInt that) { value -= that.value; if (value<0)value += MOD; return *this; } ModInt& operator*=(ModInt that) { value = (int)((long long)value * that.value % MOD); return *this; } ModInt &operator/=(ModInt that) { return *this *= that.inverse(); } ModInt operator+(ModInt that) const { return ModInt(*this) += that; } ModInt operator-(ModInt that) const { return ModInt(*this) -= that; } ModInt operator*(ModInt that) const { return ModInt(*this) *= that; } ModInt operator/(ModInt that) const { return ModInt(*this) /= that; } ModInt pow(long long k) const { if (value == 0)return 0; ModInt n = *this, res = 1; while (k) { if (k & 1)res *= n; n *= n; k >>= 1; } return res; } ModInt inverse() const { long long a = value, b = MOD, u = 1, v = 0; while (b) { long long t = a / b; a -= t * b; swap(a, b); u -= t * v; swap(u, v); } return ModInt(u); } int toi() const { return value; } private: int value; }; typedef ModInt<1000000007> mint; ostream& operator<<(ostream& os, const mint& x) { os << x.toi(); return os; } mint nPr(int n, int r, const vector &fact) { return fact[n] / fact[n - r]; } mint nCr(int n, int r, const vector &fact) { return fact[n] / (fact[r] * fact[n - r]); } mint nHr(int n, int r, const vector &fact) { return nCr(n + r - 1, r, fact); } int main(){ ios::sync_with_stdio(false); cin.tie(0); int N, K, D; cin >> N >> K >> D; vector fact(N + 1, 1); rep(i, N)fact[i + 1] = fact[i] * (i + 1); int m = 0, r = N; while (r >= K) { r -= K - 1; m++; } if (D == 1) { cout << r << endl; return 0; } mint ans = 0, pw = 1; for (int i = 0; i <= m; ++i) { int k = m - i; ans += nHr(r - 1, k, fact)*pw*r; pw *= D; } cout << ans << endl; }