#include <bits/stdc++.h>

using namespace std;

int howManyGames(int p, int d, int m, int s) {
    int count=0;
    if(s<p)
        return 0;
   else{
       s-=p;
       count++;
       p-=d;
    while(p>m && s>=p)
    {
       
        s-=p;
        count++;
         p-=d;
        
    }
       if(p<=m)
       {
           while(s>=m)
           {
               s-=m;
               count++;
               
           }
       }
   }
    return count;
}

int main() {
    int p;
    int d;
    int m;
    int s;
    cin >> p >> d >> m >> s;
    int answer = howManyGames(p, d, m, s);
    cout << answer << endl;
    return 0;
}