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
        boolean flag1=true;
        int count=0;
        int i=0;
        while(flag1){
            int curr = p-i*d;
            if(curr<=m ){
                if(s>=m){s=s-m;count++;}
                else flag1=false;
            }
            else {
               if(s>=curr){s=s-curr;count++;}
                else flag1=false; 
            }
            i++;
        }
        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();
    }
}