import java.io.*;
import java.util.*;

public class Solution {
    static long cal(long m, long n) {
        if (m == 1) return n-1;
        long mid = m % 2;
        return cal(m/2, n) + cal(m/2+mid, n) + 1;
    }
    
    
    public static void main(String[] args) {
        Scanner sc = new Scanner(System.in);
        long m, n;
        m = sc.nextLong();
        n = sc.nextLong();
        System.out.println(cal(m,n));
    }
}