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.IOException;
import java.io.InputStream;
import java.util.Arrays;


public class Template {

	public static void main(String[] args) throws IOException {
		
		FastReader sc = new FastReader(System.in);	
		
		long n = sc.nextLong();
		long k = sc.nextLong();
		
		
		if(k==1)
			System.out.println(n);
		else {
			long mst = 1;
			while(mst < n) {
				mst = mst*2 +1;
			}
			System.out.println(mst);
		}
		
		
	}

	private static long mst(long n) {
		
		for(int i = 31; i>=0; i--) {
			if((n & (1<<i)) >0)
				return i;
		}
		return 0;
	}
}





class FastReader{
    	


        byte[] buf = new byte[2048];
        int index, total;
        InputStream in;

        FastReader(InputStream is) {
            in = is;
        }

        int scan() throws IOException {
            if (index >= total) {
                index = 0;
                total = in.read(buf);
                if (total <= 0) {
                    return -1;
                }
            }
            return buf[index++];
        }

        String next() throws IOException {
            int c;
            for (c = scan(); c <= 32; c = scan()) ;
            StringBuilder sb = new StringBuilder();
            for (; c > 32; c = scan()) {
                sb.append((char) c);
            }
            return sb.toString();
        }

        int nextInt() throws IOException {
            int c, val = 0;
            for (c = scan(); c <= 32; c = scan()) ;
            boolean neg = c == '-';
            if (c == '-' || c == '+') {
                c = scan();
            }
            for (; c >= '0' && c <= '9'; c = scan()) {
                val = (val << 3) + (val << 1) + (c & 15);
            }
            return neg ? -val : val;
        }

        long nextLong() throws IOException {
            int c;
            long val = 0;
            for (c = scan(); c <= 32; c = scan()) ;
            boolean neg = c == '-';
            if (c == '-' || c == '+') {
                c = scan();
            }
            for (; c >= '0' && c <= '9'; c = scan()) {
                val = (val << 3) + (val << 1) + (c & 15);
            }
            return neg ? -val : val;
        }

    	
    }






class Entry implements Comparable<Entry> {
    private int key;
    private int value;

    public Entry(int key, int value) {
        this.key = key;
        this.value = value;
    }

    

    public int first() {
		return key;
	}



	public void setFirst(int key) {
		this.key = key;
	}



	public int second() {
		return value;
	}



	public void setSecond(int value) {
		this.value = value;
	}



	@Override
    public int compareTo(Entry other) {
        if(this.key > other.key)
        	return 1;
        else if(this.key < other.key)
        	return -1;
        else 
        	return 0;
        
    }



	public static Entry add(int i, int j) {
		
		return new Entry(i, j);
	}
}

 class Pair<First, Second> {
    private First first;
    private Second second;

    public Pair(First first, Second second) {
        this.first = first;
        this.second = second;
    }

    public void setFirst(First first) {
        this.first = first;
    }

    public void setSecond(Second second) {
        this.second = second;
    }

    public First getFirst() {
        return first;
    }

    public Second getSecond() {
        return second;
    }

    public void set(First first, Second second) {
        setFirst(first);
        setSecond(second);
    }

    @Override
    public boolean equals(Object o) {
        if (this == o) return true;
        if (o == null || getClass() != o.getClass()) return false;

        Pair pair = (Pair) o;

        if (first != null ? !first.equals(pair.first) : pair.first != null) return false;
        if (second != null ? !second.equals(pair.second) : pair.second != null) return false;

        return true;
    }

    
    
    @Override
    public int hashCode() {
        int result = first != null ? first.hashCode() : 0;
        result = 31 * result + (second != null ? second.hashCode() : 0);
        return result;
    }

    static <L,R> Pair<L,R> add(L left, R right){
        return new Pair<L,R>(left, right);
    }

	
}
 

