#include<bits/stdc++.h>
#define REP(i,n) for(int i=0,i##_len=(n);i<i##_len;++i)
#define rep(i,a,b) for(int i=int(a);i<int(b);++i)
#define All(x) (x).begin(),(x).end()
using namespace std;
using ll = long long;
constexpr ll mod=1e9+7;
int main(){
    int N,K,d;
    std::cin>>N>>K>>d;
    std::vector<std::vector<ll>> dp(2,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*i;++j){
            S[j+1] = S[j] + dp[i&1][j];
        }
        for(int j=1;j<=d*(i+1);++j){
            int ref=min(j,d*i+1);
            if(j<d) dp[(i+1)&1][j]=S[ref];
            else dp[(i+1)&1][j]=S[ref]-S[j-d];
            dp[(i+1)&1][j]%=mod;
        }
    }
    std::cout<<dp[N&1][K]<<std::endl;
}