#include <bits/stdc++.h>
using ll = long long;
using llu = long long unsigned;

using namespace std;

int main() {
    int A, B, C, D;
    cin >> A >> B >> C >> D;

    int result = 0;
    for (int i=0; i<=100; i++) {
        if ((C+1)*i > D) { result = i-1; break; }
    }
    cout << result << endl; return 0;
}