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 ans=0;
        while(s>0){
            if(ans==0){
                s=s-p;
                ans++;
            }else{
                if((p-ans*d)>m){
                    s=s-(p-ans*d);
                    ans++;
                }else if((p-ans*d)==m){
                    if(s>m){
                        s=s-m;
                        ans++;
                    }
                }
            }
        }
        System.out.println("Ans in method "+ans);
        return ans;
    
    }

    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();
    }
    
}