import java.io.*;
import java.util.*;
import java.text.*;
import java.math.*;
import java.util.regex.*;

public class Solution {

    static int howManyGames(int p, int d, int m, int s) {
        // Return the number of games you can buy
        int cn=0,ans=0,flag=0;;
        while(cn<=s)
        {
            if(p>m)
            { 
                cn+=p;
                p-=d;
                ans++;
            }
            else
            {
                cn+=m;
                ans++;
                //System.out.println(ans);
            }
        }
        //if(flag==1)
          //  return ans+1;
        //else
            return ans-1;
        
    }

    public static void main(String[] args) {
        Scanner in = new Scanner(System.in);
        int p = in.nextInt();
        int d = in.nextInt();
        int m = in.nextInt();
        int s = in.nextInt();
        int answer = howManyGames(p, d, m, s);
        System.out.println(answer);
        in.close();
    }
}