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

public class Solution {

    static int howManyGames(int priceOfGame, int discount, int minimumPrice, int availableMoney) {
        if (availableMoney < priceOfGame) {
            return 0;
        }
        
        int numberOfSelectedGames = 0;
        int priceOfNextGame = priceOfGame;
        while (availableMoney >= priceOfNextGame) {
            numberOfSelectedGames++;
            availableMoney -= priceOfNextGame;
            priceOfNextGame = calculatePriceOfNextGame(priceOfNextGame, discount, minimumPrice);
        }
        return numberOfSelectedGames;
    }
    
    static int calculatePriceOfNextGame(int priceOfNextGame, int discount, int minimumPrice) {
        if (priceOfNextGame - discount >= minimumPrice) {
            return priceOfNextGame - discount;
        } else {
            return minimumPrice;
        }
    }

    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();
    }
}