#include <bits/stdc++.h>
using namespace std;
int main()
{
    int a, b, c, d, can = -1;
    cin >> a >> b >> c >> d;
    for(int i = 0; i <= a; i++) if (i + i*c <= d && b >= i*c) can++;
    cout << (can > a ? a : can) << endl;
    return 0;
}