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.InputStreamReader;
import java.io.PrintWriter;
import java.lang.invoke.MethodHandles;
import java.nio.file.Files;
import java.nio.file.Paths;
import java.util.Arrays;
import java.util.HashMap;
import java.util.HashSet;
import java.util.List;
import java.util.Objects;
import java.util.Optional;
import java.util.Random;
import java.util.Set;
import java.util.StringTokenizer;
import java.util.stream.Collectors;

public class Main {

    public static void main(String[] args) {
        parseAndGenerate();
        try (PrintWriter out = new PrintWriter(System.out)) {
            FastScanner scanner = new FastScanner();
            long n = scanner.nextLong();
            long k = scanner.nextLong();
            if (k == 1) {
                out.println(n);
                return;
            }
            long idx = Long.highestOneBit(n);
            out.println(Long.parseLong(Long.toBinaryString(idx).replaceAll("0", "1"), 2));
        }
    }

    static final Random random = new Random();

    static void ruffleSort(long[] a) {
        // shuffle, then sort
        int n = a.length;
        for (int i = 0; i < n; i++) {
            int oi = random.nextInt(n);
            long temp = a[oi];
            a[oi] = a[i];
            a[i] = temp;
        }
        Arrays.sort(a);
    }

    static class FastScanner {

        BufferedReader br = new BufferedReader(new InputStreamReader(System.in));

        StringTokenizer st = new StringTokenizer("");

        String next() {
            while (!st.hasMoreTokens()) {
                try {
                    st = new StringTokenizer(br.readLine());
                } catch (IOException e) {
                    e.printStackTrace();
                }
            }
            return st.nextToken();
        }

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

        long[] readArray(int n) {
            long[] a = new long[n];
            for (int i = 0; i < n; i++) {
                a[i] = nextLong();
            }
            return a;
        }

        Integer[] readArrayInt(int n) {
            Integer[] a = new Integer[n];
            for (int i = 0; i < n; i++) {
                a[i] = nextInt();
            }
            return a;
        }

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

    static class Pair {

        int first;

        int second;

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

        @Override
        public boolean equals(Object o) {
            if (this == o) {
                return true;
            }
            if (o == null || getClass() != o.getClass()) {
                return false;
            }
            Pair pair = (Pair) o;
            return first == pair.first && second == pair.second;
        }

        @Override
        public int hashCode() {
            return Objects.hash(first, second);
        }
    }

    static class Equation {

        // ax+by=c;
        int a, b, c;

        public Equation(int x1, int y1, int x2, int y2) {
            int a = y2 - y1;
            int b = x1 - x2;
            int c = a * x1 + b * y1;
        }

        public Equation(int a, int b, int c) {
            this.a = a;
            this.b = b;
            this.c = c;
        }

        public boolean isPointOnLine(int x, int y) {
            return a * x + b * y == c;
        }
    }

    private static void buildGraph(HashMap<Integer, Set<Integer>> map, int first, int second) {
        Set<Integer> set = map.getOrDefault(first, new HashSet<>());
        set.add(second);
        map.put(first, set);
        set = map.getOrDefault(second, new HashSet<>());
        set.add(first);
    }

    public static void parseAndGenerate() {
    }

    private static void print2dArr(PrintWriter out, int[][] arr) {
        for (int i = 0; i < arr.length; i++) {
            for (int j = 0; j < arr[i].length; j++) {
                out.print(arr[i][j] + " ");
            }
            out.println();
        }
    }

    private static boolean[] sieve(int n) {
        boolean[] isPrime = new boolean[n + 1];
        Arrays.fill(isPrime, true);
        isPrime[0] = isPrime[1] = false;
        for (int i = 2; i <= n; i++) {
            if (isPrime[i] && ((long) i * i) <= n) {
                for (int j = i * i; j <= n; j += i) {
                    isPrime[j] = false;
                }
            }
        }
        return isPrime;
    }
}
