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.BufferedReader;
import java.io.IOException;
import java.io.InputStream;
import java.io.InputStreamReader;
import java.io.PrintWriter;
import java.util.ArrayList;
import java.util.HashMap;
import java.util.HashSet;
import java.util.StringTokenizer;
import java.util.TreeMap;
import java.util.TreeSet;

public class b {
	

	public static void main(String args[]) throws IOException {
		FastScanner in = new FastScanner(System.in);
		PrintWriter out = new PrintWriter(System.out);
		//BEGIN HERE
		long n = in.nextLong();
		long k = in.nextLong();
	
		if(k == 1 ) {
			System.out.println(n);
		} else {
			for(int i = 63; i >= 0; i--) {
				if((n & ( 1l<<i)) != 0) {	
					if(i == 63) {
						System.out.println(Long.MAX_VALUE);
					}
					else {
						System.out.println((1l<<(i+1))-1l);
					}
					return;
					
				}
			}
		}
		out.close();
	}

	static class FastScanner {
		BufferedReader br;
		StringTokenizer st;

		public FastScanner(InputStream i) {
			br = new BufferedReader(new InputStreamReader(i));
			st = null;
		}

		public String next() throws IOException {
			while (st == null || !st.hasMoreTokens())
				st = new StringTokenizer(br.readLine());
			return st.nextToken();
		}

		public String nextLine() throws IOException {
			if (st == null) {
				st = new StringTokenizer(br.readLine());
			}
			String line = st.nextToken("\n");
			st = null;
			return line;
		}

		public int nextInt() throws IOException {
			return Integer.parseInt(next());
		}

		public long nextLong() throws IOException {
			return Long.parseLong(next());
		}

		public double nextDouble() throws IOException {
			return Double.parseDouble(next());
		}
	}

	public static class combinatorics {
		static long modInv(long a, long b) {
			return 1 < a ? b - modInv(b % a, a) * b / a : 1;
		}

		static long factorial[], mod;

		combinatorics(int n, long MOD) {
			mod = MOD;
			factorial = new long[n + 1];
			factorial[0] = 1;
			for (int i = 1; i <= n; i++) {
				factorial[i] = i * factorial[i - 1];
				factorial[i] %= mod;
			}
		}

		static long nCr(int n, int r) {
			if (r > n)
				return 0;
			return (factorial[n] * modInv((factorial[n - r] * factorial[r]) % mod, mod)) % mod;
		}

		static long gcd(long a, long b) {
			return b == 0 ? a : gcd(b, a % b);
		}

		static long lcm(long a, long b) {
			return a * (b / gcd(a, b));
		}
	}

	public static class DisjointSet {
		int p[], r[], s[];
		int numDisjoint;

		DisjointSet(int N) {
			numDisjoint = N;
			r = new int[N];
			s = new int[N];
			p = new int[N];
			for (int i = 0; i < N; i++)
				p[i] = i;
		}

		int findSet(int i) {
			return (p[i] == i) ? i : (p[i] = findSet(p[i]));
		}

		boolean isSameSet(int i, int j) {
			return findSet(i) == findSet(j);
		}

		void unionSet(int i, int j) {
			if (!isSameSet(i, j)) // if from different set
			{
				numDisjoint--;
				int x = findSet(i), y = findSet(j);
				if (r[x] > r[y]) {
					p[y] = x; // rank keeps the tree short
					s[x] += s[y];
				} else {
					p[x] = y;
					if (r[x] == r[y])
						r[y]++;
					s[y] += s[x];
				}
			}
		}

		int sizeOfSet(int i) {
			return s[findSet(i)];
		}
	};

}
