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

int main() {
    int a, b, c, d;
    cin >> a >> b >> c >> d;
    
    int ans = 0;
    for (int i = 0; i <= a; i++) {
        int res = i + i * c;
        if (res <= d and i * c <= b) ans = i;
    }
    cout << ans << endl;
    return 0;
}