#include<cstdio>
#include<cstdlib>
#include<cstring>
#include<cmath>
//#include<cctype>
#include<climits>
#include<iostream>
#include<string>
#include<vector>
#include<map>
//#include<list>
#include<queue>
#include<deque>
#include<algorithm>
//#include<numeric>
#include<utility>
#include<complex>
//#include<memory>
#include<functional>
#include<cassert>
#include<set>
#include<stack>

const int dx[] = {1, 0, -1, 0};
const int dy[] = {0, 1, 0, -1};
using namespace std;
typedef long long ll;
typedef vector<int> vi;
typedef vector<ll> vll;
typedef pair<int, int> pii;

int N, S, K;
const ll MOD = 1e9+7;
const int MAXN = 101, MAXS = 20010;
ll dp[MAXN][MAXS];

ll dfs(int n, int y) {
    if (y < 0) return 0;
    if (n == N-1) return 1;
    ll& ret = dp[n][y];
    if (ret >= 0) return ret;
    ret = 0;
    for (int i = 0; i*(N-n) <= y; i++) {
        ret += dfs(n+1, y-i*(N-n));
    }
    ret %= MOD;
    return ret;
}

int main() {
    cin.tie(0);
    ios::sync_with_stdio(false);
    cin >> N >> S >> K;
    S -= N*(N-1)/2 * K;
    memset(dp, -1, sizeof(dp));
    cout << dfs(0, S) << endl;
    return 0;
}