// No.269 見栄っ張りの募金活動

#include <bits/stdc++.h>
using namespace std;
typedef long long ll;
// const int INF = 2147483647;
// const ll INF = 9223372036854775807;
const ll MOD = 1e9 + 7;

int dp[101][20001];

int main() {
	int N, S, K;
	cin >> N >> S >> K;

	for (int j=0; j<=S; j++) {
		if (j % N == 0) {
			dp[1][j] = 1;
		}
	}

	for (int i=2; i<=N; i++) {
		for (int j=0; j<=S; j++) {
			if (j - K*(N-i+1) < 0) continue;

			if (j - (N-i+1) < 0) {
				dp[i][j] = dp[i-1][j - K*(N-i+1)];
			} else {
				dp[i][j] = (dp[i-1][j - K*(N-i+1)] + dp[i][j - (N-i+1)]) % MOD;
			}
		}
	}

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

	// **** debug ****
	/*
	for (int i=1; i<=N; i++) {
		cout << "i=" << i << " ";
		for (int j=0; j<=S; j++) {
			cout << dp[i][j] << " ";
		}
		cout << endl;
	}
	*/

	return 0;
}