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 count=0;
        while(s>=0)
        {
            if(p>m )
            {
                s-=(p);
                p=p-d;
                count++;
            //System.out.println(s);
                if(s<0)
                {
                    count--;//20 3 6 85
                }
            }
            else
            {
                s-=m;
                count++;
            //System.out.println(count);
            if(s<0)
                count--;
            }
        }
        return count;
    }


    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();
    }
}