#include<iostream>
#include<vector>
#include<algorithm>
#include<utility>
typedef long long ll;
constexpr ll mod = 1e9+7;

int main(){
    ll N,K,d;
    std::cin>>N>>K>>d;
    std::vector<std::vector<ll>> dp(N+1,std::vector<ll>(N*d+1,0));
    std::vector<ll> S(d*N+2,0);
    dp[0][0]=1;
    for(int i=0;i<N;++i){
        for(int j=0;j<d*N+1;++j){
            S[j+1] = (S[j] + dp[i][j])%mod;
        }
        for(int j=0;j<d*N+1;++j){
            if(j<d) dp[i+1][j]=S[j];
            else dp[i+1][j]=S[j]-S[j-d]+mod;
            dp[i+1][j]%=mod;
        }
    }
    std::cout<<dp[N][K]<<std::endl;
}