#include <iostream>
#include <vector>
#include <algorithm>
using namespace std;

#define RREP(i,s,e) for (i = s; i >= e; i--)
#define rrep(i,n) RREP(i,n,0)
#define REP(i,s,e) for (i = s; i < e; i++)
#define rep(i,n) REP(i,0,n)
#define INF 100000000
#define MOD 1000000007

typedef long long ll;

int main() {
    int i, j, n, s, k;
    int dp[100][20001] {};
    cin >> n >> s >> k;
    s -= n * (n-1) * k / 2;
    rep (i,s/n+1)
        dp[0][i*n] = 1;
    REP (i,1,n) {
        rep (j,s+1) {
            dp[i][j] = (dp[i-1][j] + (n-i <= j ? dp[i][j-(n-i)] : 0)) % MOD;
        }
    }
    cout << dp[n-1][s] << endl;
    return 0;
}