#include <iostream>
using namespace std;
#define ll long long
ll dp[101][20001];
int main(){
    int n, s, k;
    cin >> n >> s >> k;
    dp[n][0] = 1;
    for(int i=n-1; i>=0; --i){
        for(int j=0; j<=s; ++j){
            for(int v=0; v<=j; ++v){
                int w=v+(v+k)*(n-1-i);
                if(j<w) break;
                dp[i][j] += dp[i+1][j-w];
                dp[i][j] %= 1000000007;
            }
        }
    }
    cout << dp[0][s] << endl;
    return 0;
}