#include <iostream>
#include <vector>
#include <string>
#include <algorithm>
#include <cstdio>
#include <cstring>
#include <cmath>
using namespace std;
using ll = long long;

int main() {
    int a, b, c, d;
    cin >> a >> b >> c >> d;

    cout << min(min(d / (c + 1), a), b / c) << endl;

    return 0;
}