#include <cstdio>
#include <iostream>
#include <algorithm>
#include <complex>
#include <queue>
#include <map>
#include <string>
using namespace std;

#define FOR(i,a,b) for (int i=(a);i<(b);i++)
#define FORR(i,a,b) for (int i=(b)-1;i>=(a);i--)
#define REP(i,n) for (int i=0;i<(n);i++)
#define RREP(i,n) for (int i=(n)-1;i>=0;i--)
#define pb push_back
#define ALL(a) (a).begin(),(a).end()

#define PI 3.1415926535

typedef long long ll;
typedef pair<int, int> P;
//typedef complex<double> C;

const int MAX_N = 100;
const int MAX_S = 20000;

const ll mod = 1000000007;

int N, S, K;
ll dp[MAX_N][MAX_S + 1];

void input() {
	cin >> N >> S >> K;
}

void solve() {
	int s = 0;
	while (s <= S) {
		dp[0][s] = 1;
		s += N;
	}
	FOR(i, 1, N) {
		FOR(j, K * (N - i), S + 1) {
			dp[i][j] = dp[i - 1][j - K * (N - i)] + dp[i][j - (N - i)];
			dp[i][j] %= mod;
		}
	}
	cout << dp[N - 1][S] << endl;
}

int main() {
	input();
	solve();
}