#include "bits/stdc++.h"
using namespace std;
#define ll long long int
#define rep(i,n) for( int i = 0; i < n; i++ )
#define rrep(i,n) for( int i = n; i >= 0; i-- )
#define REP(i,s,t) for( int i = s; i <= t; i++ )
#define RREP(i,s,t) for( int i = s; i >= t; i-- )
#define dump(x)  cerr << #x << " = " << (x) << endl;
#define INF 2000000000
#define mod 1000000007
#define INF2 1000000000000000000
#define int long long

int dp[110][20110];


signed main(void)
{
    cin.tie(0);
    ios::sync_with_stdio(false);
	int N, S, K;
	cin >> N >> S >> K;
	dp[N + 1][S] = 1;
	RREP(i, N, 1) {
		RREP(j, S, 0) {
			int k;
			if (i == N) k = 0;
			else k = K;
			while (j >= i * k) {
				dp[i][j - i * k] = (dp[i][j - i * k] + dp[i + 1][j]) % mod;
				k++;
			}
		}
	}
	//RREP(i, N, 1) {
	//	RREP(j, S, 0) {
	//		cout << i << " " << j << " " << dp[i][j] << endl;
	//	}
	//}
	cout << dp[1][0] << endl;

    return 0;
}