#include <bits/stdc++.h>

using namespace std;

int main() {
    int p;
    int d;
    int m;
    int s;
    cin >> p >> d >> m >> s;
    int count=0;
    while(s>=0)
    {
        if(p>m)
        {
            s = s - p;
            p = p-d;
        }
        else
        {
            s = s-m;
        }
          count++;  
    }
    cout << count-1 <<endl;
    return 0;
}