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) 
    {
        
        int c=0;
        while (s>0)
        {
            if (p>=m)
            {
            s=s-p;
            p=p-d;
            c=c+1;
            }
            else
            {
                s=s-m;
                c=c+1;
            }
            if (s<0)
            {
                c=c-1;
            }
        }
        return (c);        
        // Return the number of games you can buy
    }

    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();
    }
}