Since Grisha behaved well last year, at New Year's Eve he was visited by Ded Moroz who brought an enormous bag of gifts with him! The bag contains n sweet candies from the good ol' bakery, each labeled from 1 to n corresponding to its tastiness. No two candies have the same tastiness.

The choice of candies has a direct effect on Grisha's happiness. One can assume that he should take the tastiest ones — but no, the holiday magic turns things upside down. It is the xor-sum of tastinesses that matters, not the ordinary sum!

A xor-sum of a sequence of integers a1, a2, ..., am is defined as the bitwise XOR of all its elements: <image>, here <image> denotes the bitwise XOR operation; more about bitwise XOR can be found [here.](https://en.wikipedia.org/wiki/Bitwise_operation#XOR)

Ded Moroz warned Grisha he has more houses to visit, so Grisha can take no more than k candies from the bag. Help Grisha determine the largest xor-sum (largest xor-sum means maximum happiness!) he can obtain.

Input

The sole string contains two integers n and k (1 ≤ k ≤ n ≤ 1018).

Output

Output one number — the largest possible xor-sum.

Examples

Input

4 3


Output

7


Input

6 6


Output

7

Note

In the first sample case, one optimal answer is 1, 2 and 4, giving the xor-sum of 7.

In the second sample case, one can, for example, take all six candies and obtain the xor-sum of 7.
import java.io.*;

import java.util.*;
 public class Solution {
	 
	
	 public static void main(String[] args) throws Exception
    {
		 FastReader fr=new FastReader();
		 long n=fr.nextLong();
		 long k=fr.nextLong();
		 if(k==1)
			 System.out.println(n);
		 else {
			 long res=1;
			 while(res<=n) {
				 res<<=1;
			 }
			 System.out.println(res-1);
		 }
		
		  
		
		 
	}
	 
	 
	 
	
	public static long gcd(long n1,long n2) {
		 if (n2 == 0) {
		        return n1;
		    }
		    return gcd(n2, n1 % n2);
	}
	 public static boolean isPali(String s) {
		 int i=0;
		 int j=s.length()-1;
		 while(i<=j) {
			 if(s.charAt(i)!=s.charAt(j))
				 return false;
			 i++;
			 j--;
		 }
		 return true;
	 }
	 public static String reverse(String s) {
		 String res="";
		 for(int i=0;i<s.length();i++) {
			 res+=s.charAt(i);
		 }
		 return res;
	 }
	
		
	 
	 public static int bsearch(long suf[],long val) {
		 int i=0;
		 int j=suf.length-1;
		 while(i<=j) {
			 int mid=(i+j)/2;
			 if(suf[mid]==val)
				 return mid;
			 else if(suf[mid]<val)
				 j=mid-1;
			 else
				 i=mid+1;
		 }
		 return -1;
	 }
	 
	 
	 
	
	 
	 
	public static int[] getFreq(String s) {
		int a[]=new int[26];
		for(int i=0;i<s.length();i++) {
			a[s.charAt(i)-'a']++;
		}
		return a;
		
	}
	 
	 public static boolean isPrime(int n) {
		 
		 for(int i=2;(i*i)<=n;i++) {
			 if(n%i==0)
				 return false;
		 }
		 return true;
	 }
            	  
             
             
    }
class Pair implements Comparable<Pair>{
	int cost;
	int type;
	
	Pair(int cost,int type){
		this.cost=cost;
		
		this.type=type;
	}
	public int compareTo(Pair o) {
		return o.type-this.type;
	}
}

	
	 
	
	

	 
 
  

class FastReader
{
    BufferedReader br;
    StringTokenizer st;
 
    public FastReader()
    {
        br = new BufferedReader(new
                InputStreamReader(System.in));
    }
 
    String next()
    {
        while (st == null || !st.hasMoreElements())
        {
            try
            {
                st = new StringTokenizer(br.readLine());
            }
            catch (IOException e)
            {
                e.printStackTrace();
            }
        }
        return st.nextToken();
    }
 
    int nextInt()
    {
        return Integer.parseInt(next());
    }
 
    long nextLong()
    {
        return Long.parseLong(next());
    }
 
    double nextDouble()
    {
        return Double.parseDouble(next());
    }
 
    String nextLine()
    {
        String str = "";
        try
        {
            str = br.readLine();
        }
        catch (IOException e)
        {
            e.printStackTrace();
        }
        return str;
    }
}

