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 count =0,sum=0;
        int cost = 0;
        for(int i=0;sum<=s;i++)
        {
            if(p-(i*d) <= m)
            {
                cost = m;
            }
            else
            {
                cost = p-i*d;
            }
            sum = sum + cost;
            if(sum<=s)
            {
            count = count + 1;
            }
            else
            {
                return 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();
    }
}