#include <cmath>
#include <cstdio>
#include <vector>
#include <iostream>
#include <algorithm>
using namespace std;


int main() {
    int p,d,m,s,games=0;
    cin>>p>>d>>m>>s;
    while(s>=m&&s>=p){
        if(p>m)
        {
            s=s-p;
            games++;
            p=p-d;
        }
        else
        {
            s=s-m;
            games++;
        }
        //cout<<s<<" ";
    }
    cout<<games;
    return 0;
}