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


int main() {
   int p,d,m,s;
    int n;
    cin>>p>>d>>m>>s;
    for(s;s>0;){
        if(p>m){
            s-=p;
            p-=d;
            n++;
            
        }
        else{
            s-=m;
            n++;
            
        }
        
    }
    
   
    if(s<0){cout<<n-1;}
    else{cout<<n;}
    
    return 0;
}