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 n=0;
                    if (s>p){n++;s=s-p;}
int h=p-d;
       
        
            while  (s>h && s>m)
            {
               int g=p-d;
                n++;
                s=s-g;
               }
            while (s>=0){
                n++;
                s=s-m;
               
                   
                    
          }
                
            
        
        return n;}
    
    

    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();
    }
}