import java.util.Scanner;

public class Main {
	public static void main(String[] args) throws Exception {
		Scanner sc = new Scanner(System.in);
		int n = sc.nextInt();
		int m = sc.nextInt();
		sc.close();

		if (n < 32 && 1 << (n - 1) < m) {
			long ans = 0;
			for (int i = 0; i < n; i++) {
				ans += 1 << i;
			}
			System.out.println(ans);
		} else {
			int p = m;
			long ans = m;
			for (int i = 1; i < n; i++) {
				if (p == 1) {
					ans += n - i;
					break;
				}
				if (p % 2 == 0) {
					p = p / 2;
				} else {
					p = p / 2 + 1;
				}
				ans += p;
			}
			System.out.println(ans);
		}
	}
}