import java.io.*;
import java.util.*;
import java.text.*;
import java.math.*;
import java.util.regex.*;

public class ertro {

    static int howManyGames(int p, int d, int m, int s) {
        // Return the number of games you can buy
        int games=0;
        while(s-Integer.max(p,m)>=0){
            s-=Integer.max(p,m);
            p=p>m?p-d:p;
            games++;
        }
        return games;
    }

    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();
    }
}