#include<bits/stdc++.h>
using namespace std;
typedef long long ll;

const int MAX_N = 100100;
const int MAX_K = 150;
const int MOD = 1e9+7;

int PartNum[MAX_N][MAX_K];
// dp[i][j]で、jのi分割数

void calcPartNum() {
	PartNum[0][0] = 1;
	for (int n = 0; n < MAX_N; ++n) {
		for (int k = 1; k < MAX_K; ++k) {	
			PartNum[n][k] = PartNum[n][k - 1];
			if (n >= k) {
				PartNum[n][k] += PartNum[n - k][k];
				if (PartNum[n][k] >= MOD) PartNum[n][k] -= MOD;
			}
		}
	}
}

int main(){
  int N,S,K; cin >> N >> S >> K;
  
  for(int i = 0; i < MAX_N; i++){
    for(int j = 0; j < MAX_K; j++){
      PartNum[i][j] = 0;
    }
  }
  
  calcPartNum();

  int res = S; res -= (N*(N-1)*K)/2;
  if( res < 0){ cout << 0 << endl; return 0;}
  cout << PartNum[res][N] << endl; return 0;}