#include<bits/stdc++.h>
using namespace std;
#define g(a,b) (a % b + b) % b
int main()
{
int f[1001][1001],n, s, a, b;
cin>>n>>s>>a>>b;
f[0][0] = 1;
for (int i = 1; i < n; i++)
for (int j = 0; j < n; j++)
f[i][j] = (f[i - 1][g(j - (n - i) * a, n)] + f[i - 1][g(j + (n - i) * b, n)]) % 100000007;
cout<<f[n - 1][g(s, n)];
return 0;
}