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();

		int[] a = new int[n];
		a[0] = m;
		long ans = m;
		for (int i = 1; i < n; i++) {
			if (a[i - 1] % 2 == 0) {
				a[i] = a[i - 1] / 2;
			} else {
				a[i] = a[i - 1] / 2 + 1;
			}
			ans += a[i];
		}
		System.out.println(ans);
	}
}