import java.util.Arrays;
import java.util.LinkedList;
import java.util.Scanner;

public class Main {
	
	public static long MOD = 1000000007;
	
	public static void main(String[] args) {
		Scanner sc = new Scanner(System.in);
		
		final long N = sc.nextInt();
		
		final long X = sc.nextLong();
		final long A = sc.nextLong();
		final long B = sc.nextLong();
		
		
		final long A_time = (X + A - 1) / A;
		final long B_time = (((1l << (N - 1)) - X) + B - 1) / B;
		
		//System.out.println((1 << (N - 1)) + " " + X);
		//System.out.println(A_time + " " + B_time);
		
		System.out.println(Math.min(A_time, B_time));
	}
}