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
        ArrayList<Integer> prices = new ArrayList<>();
        while(p>m){
            prices.add(p);
            p = p-d;
        }
        for(int i=0;i<10000;i++){
            prices.add(m);
        }
        int count=0;
        for(int j=0;j<10000;j++){
            s = s-prices.get(j);
            count++;
            if(s<0){
                count--;
                break;
            }
        }


        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();
    }
}