#include <bits/stdc++.h>

using namespace std;

int main() {
    cin.tie(0);
    ios::sync_with_stdio(false);
    const long long MOD = 1000000007;
    int n, s, k;
    cin >> n >> s >> k;
    if (s >= n * (n - 1) * k / 2) s -= n * (n - 1) * k / 2;
    else {
        cout << 0 << "\n";
        return 0;
    }
    vector< vector<long long> > dp(n + 1, vector<long long>(s + 1,0)); 
    dp[0][0] = 1;
    for(int i = 1; i <= n; i++) {
        for(int j = 0; j <= s; j++) {
            for(int t = 0; t * (n - i + 1) <= j; t++) {
                dp[i][j] += dp[i - 1][j - (n - i + 1) * t];
                dp[i][j] %= MOD;
            }
        }
    }
    cout << dp[n][s] << "\n";
    return 0;
}