#include <iostream>
#include <vector>
#include <algorithm>
#include <cmath>
#include <iomanip>
#include <stack>
#include <algorithm>
#include <string>
#include <map>
#include <iterator>
#include <set>
#include <queue>

using namespace std;


int main() {

    int A, B, C, D;
    cin >> A >> B >> C >> D;
    long res = 0;
    for (int a = 0; a <= A; ++a) {
        if ((C * a <= B) and (a + C * a <= D)) {
            res = a;
        } else {
            break;
        }
    }

    cout << res << endl;

    return 0;

}