#define rep(i, n) for (int i = 0; i < (int)(n); i++)
#define ALL(v) v.begin(), v.end()
typedef long long ll;

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

const int MOD=1e9+7;
ll dp[20202][110];

int main(){
  int n,s,k;
  cin>>n>>s>>k;
  if(s-(n-1)*n*k/2<0){
    cout<<0<<endl;
    return 0;
  }
  
  dp[0][0]=1;
  for(int i=0;i<=s-(n-1)*n*k/2;i++){
    for(int j=1;j<=n;j++){
      if(i>=j) dp[i][j]=(dp[i-j][j]+dp[i][j-1])%MOD;
      else dp[i][j]=dp[i][j-1];
    }
  }
  cout<<dp[s-(n-1)*n*k/2][n]<<endl;
  
  return 0; 
}