#include "bits/stdc++.h"
 
using namespace std;
typedef long long int ll;
typedef pair<ll, ll > pi;  
typedef pair<pair<ll, ll >, ll > pii;  
vector<ll > vec;
vector<vector<ll > > vec2;
ll MOD = 1000000007;
ll INF = 1145141919454519;

int main(){

    ll N, d, K;
    cin >> N >> d >> K;
    //Nと段数
    vector<map<ll, ll > > dp(N+19);
    dp[0][0] = 1;

    for(ll i = 0; i < N; i++){
        //更新
        auto begin = dp[i].begin(), end = dp[i].end();
        for (auto iter = begin; iter != end; iter++) {
            ll now = iter->first;
            ll num = iter->second;
            //cout << now << " ";
            //遷移
            if((now) + (N - i - 1) * d < K) continue;
            for(ll h = d; h > 0; h--){
                //枝ヶ里
                if((now + h) + (N - i - 1) * d < K) break;
                if(now + h <= K){
                    dp[i+1][now+h] += num;
                    dp[i+1][now+h] %= MOD;
                }
            }
        }  
        //cout << endl;
    }

    cout << dp[N][K] << endl;

}