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 money = s;
		int count = 0;
		int x = 10000;
		while(x > 0 && p > 0){

			if(money <= m && money > 0){
				money = money - m;
				count++;
			}
			else{
				money = money - p;
				count++;
				p = p - d; 	
			}
			// money = money - p;
			// System.out.println("While: "+money);
			// count++;
			// p = p - d;
			x--;
		}
        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();
    }
}