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