#include <iostream>
#include <cstdio>
#include <cstring>
using namespace std;
const int N = 1e3 + 5;
const int MOD = 100000007;

int n, s, a, b;
int dp[N][N];

int func(int x)
{
    return (x % n + n) % n;
}

int main()
{
    scanf("%d %d %d %d", &n, &s, &a, &b);
    dp[1][func((n-1) * a)] = 1;
    dp[1][func((n-1) * (-b))] = 1;
    for (int i = 2; i < n; ++i)
    {
        for (int j = 0; j < n; ++j) 
        {
            dp[i][j] = (dp[i-1][func(j-(n-i)*a)] + dp[i-1][func(j+(n-i)*b)]) % MOD;
        }
    }
    printf("%d", dp[n-1][func(s)]);
    return 0;
}