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;
        if(s-p>0)
        {s-=p;c++;
        while(s>=0)
        {
            if(p-d>m)
            { p-=d; s-=p; c++;}
            else
            {  s-=m; c++;}
        }
        }
        return s<0?c-1:c;
    }

    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();
    }
}