#include <iostream>
using namespace std;

int N, S, K;

long long DP[101][20001];

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

	DP[0][0] = 1;
	for (int k = 0; k*N <= S; k++) {
		DP[1][k*N] += DP[0][0];
	}
	for (int i = 1; i < N; i++) {
		for (int j = 0; j <= S; j++) {
			if(DP[i][j]!=0 && j + K*(N - i) <= S) {
				DP[i + 1][j + K*(N - i)] += DP[i][j];
				DP[i + 1][j + K*(N - i)] %= (int)1e9 + 7;
			}

			if (DP[i+1][j] != 0 && j + 1 * (N - i) <= S) {
				DP[i+1][j + N - i] += DP[i+1][j];
				DP[i + 1][j + N - i] %= (int)1e9 + 7;
			}
		}
	}

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

	return 0;
}