#define _CRT_SECURE_NO_WARNINGS
#include <stdio.h>
#include <string.h>
#include <iostream>
#include <sstream>
#include <algorithm>
#include <stack>
#include <vector>
#include <queue>
#include <map>
#include <set>
#include <deque>
#include <functional>
#define _USE_MATH_DEFINES
#include <math.h>
#include <complex>
using namespace std;

//#include <atcoder/all>
//using namespace atcoder;

#define REP(i,n) for(int i = 0; i < (int)n; i++)
#define RREP(i,n) for(int i = (int)n-1; i >= 0; i--)
#define LREP(i,n) for(LL i = 0; i < (LL)n; i++)

#define Vi vector<int>
#define Vl vector<long long>
#define LP pair<long long ,long long>
#define P pair<int, int>
#define T3 tuple<LL, LL, LL>
#define T4 tuple<LL, LL, LL, LL>
#define INF 1000000007
#define SIZE	200010
#define MOD 1000000007
typedef long long LL;

int N, S, K;
LL dp[110][20010];

int main() {
	cin >> N >> S >> K;

	dp[0][0] = 1;
	for (int i = 1; i < N; i++) {
		for (int s = 0; s <= S; s++) {
			dp[i][s] = dp[i - 1][s];
			if (s - i >= 0) dp[i][s] += dp[i][s - i];
			dp[i][s] %= MOD;
		}
	}

	LL ans = 0;
	for (int a = 0; a <= S; a++) {
		int s = S - N * a - N * (N - 1) * K / 2;
		if (s >= 0) ans = (ans + dp[N - 1][s]) % MOD;
	}
	cout << ans << endl;
}