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


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