At first, let's define function f(x) as follows: $$$ \begin{matrix} f(x) & = & \left\{ \begin{matrix} x/2 & \mbox{if } x  is even \\\ x - 1 & \mbox{otherwise } \end{matrix} \right. \end{matrix} $$$

We can see that if we choose some value v and will apply function f to it, then apply f to f(v), and so on, we'll eventually get 1. Let's write down all values we get in this process in a list and denote this list as path(v). For example, path(1) = [1], path(15) = [15, 14, 7, 6, 3, 2, 1], path(32) = [32, 16, 8, 4, 2, 1].

Let's write all lists path(x) for every x from 1 to n. The question is next: what is the maximum value y such that y is contained in at least k different lists path(x)?

Formally speaking, you need to find maximum y such that \left| \{ x ~|~ 1 ≤ x ≤ n, y ∈ path(x) \} \right| ≥ k.

Input

The first line contains two integers n and k (1 ≤ k ≤ n ≤ 10^{18}).

Output

Print the only integer — the maximum value that is contained in at least k paths.

Examples

Input


11 3


Output


5


Input


11 6


Output


4


Input


20 20


Output


1


Input


14 5


Output


6


Input


1000000 100


Output


31248

Note

In the first example, the answer is 5, since 5 occurs in path(5), path(10) and path(11).

In the second example, the answer is 4, since 4 occurs in path(4), path(5), path(8), path(9), path(10) and path(11).

In the third example n = k, so the answer is 1, since 1 is the only number occuring in all paths for integers from 1 to 20.
/**
 * BaZ :D
 */
import java.util.*;
import java.io.*;
import static java.lang.Math.*;

public class ACMIND
{
    static FastReader scan;
    static PrintWriter pw;
    static long MOD = 1_000_000_007 ;
    static long INF = 1_000_000_000_000_000_000L;
    static long inf = 2_000_000_000;
    public static void main(String[] args) {
        new Thread(null,null,"BaZ",1<<27)
        {
            public void run()
            {
                try
                {
                    solve();
                }
                catch(Exception e)
                {
                    e.printStackTrace();
                    System.exit(1);
                }
            }
        }.start();
    }
    static long n,k,dp[][][][];
    static char digs[];
    static void solve() throws IOException
    {
        scan = new FastReader();
        pw = new PrintWriter(System.out,true);
        StringBuilder sb = new StringBuilder();
        n = nl();
        k = nl();
        long num = 0;
        for(int i=59;i>=0;--i) {
            long set_krke = calc(num|(1L<<i));
            //pl("num: "+num+" i: "+i+" set : "+set_krke);
            if(set_krke>=k) {
                num|=(1L<<i);
            }
        }
        pl(num);
        pw.flush();
        pw.close();
    }
    static long calc(long prefix) {
        //pl("Prefix : "+prefix);
        digs = Long.toBinaryString(prefix).toCharArray();
        //pa("digs", digs);
        dp = new long[61][3][61][2];
        for(int i=0;i<=60;++i) {
            for(int j=0;j<3;++j) {
                for(int k=0;k<=60;++k) {
                    Arrays.fill(dp[i][j][k], -1);
                }
            }
        }
        long ans = f(60, 0, 0, 0);

        if((prefix&1)==0) {
            dp = new long[61][3][61][2];
            for(int i=0;i<=60;++i) {
                for(int j=0;j<3;++j) {
                    for(int k=0;k<=60;++k) {
                        Arrays.fill(dp[i][j][k], -1);
                    }
                }
            }
            digs = Long.toBinaryString(prefix+1).toCharArray();
            ans+=f(60, 0, 0, 0);
        }
        return ans;
    }
    static long f(int index, int started_appending_num, int pos, int already_smaller) {
        //pl("index: "+index+" pos : "+pos);
        if(index==-1) {
            if(pos==digs.length) {
                return 1;
            }
            return 0;
        }
        if(dp[index][started_appending_num][pos][already_smaller] != -1) {
            return dp[index][started_appending_num][pos][already_smaller];
        }
        int bit = (((n & (1L<<index)) != 0 )? 1 : 0);
        long ways = 0;
        if(started_appending_num == 0) {
            //append a 0
            ways+=f(index-1, started_appending_num, 0, already_smaller | (bit > 0 ? 1 : 0));
            //start appending num
            if(already_smaller==1 || bit==1) {
                ways+=f(index-1, 1,1, already_smaller);
            }
        }
        else if(started_appending_num == 1 && pos < digs.length) {
            if(already_smaller==1 || (bit >= digs[pos] - '0')) {
                ways+=f(index-1, 1, pos+1, already_smaller | (bit>digs[pos] - '0' ? 1 : 0));
            }
        }
        else {
            ways+=f(index-1, started_appending_num, pos, already_smaller | bit);
            if(already_smaller==1 || bit==1) {
                ways+=f(index-1, started_appending_num, pos, already_smaller);
            }
        }
        return dp[index][started_appending_num][pos][already_smaller] = ways;
    }
    static int ni() throws IOException
    {
        return scan.nextInt();
    }
    static long nl() throws IOException
    {
        return scan.nextLong();
    }
    static double nd() throws IOException
    {
        return scan.nextDouble();
    }
    static void pl()
    {
        pw.println();
    }
    static void p(Object o)
    {
        pw.print(o+" ");
    }
    static void pl(Object o)
    {
        pw.println(o);
    }
    static void psb(StringBuilder sb)
    {
        pw.print(sb);
    }
    static void pa(String arrayName, Object arr[])
    {
        pl(arrayName+" : ");
        for(Object o : arr)
            p(o);
        pl();
    }
    static void pa(String arrayName, int arr[])
    {
        pl(arrayName+" : ");
        for(int o : arr)
            p(o);
        pl();
    }
    static void pa(String arrayName, long arr[])
    {
        pl(arrayName+" : ");
        for(long o : arr)
            p(o);
        pl();
    }
    static void pa(String arrayName, double arr[])
    {
        pl(arrayName+" : ");
        for(double o : arr)
            p(o);
        pl();
    }
    static void pa(String arrayName, char arr[])
    {
        pl(arrayName+" : ");
        for(char o : arr)
            p(o);
        pl();
    }
    static void pa(String listName, List list)
    {
        pl(listName+" : ");
        for(Object o : list)
            p(o);
        pl();
    }
    static void pa(String arrayName, Object[][] arr) {
        pl(arrayName+" : ");
        for(int i=0;i<arr.length;++i) {
            for(Object o : arr[i])
                p(o);
            pl();
        }
    }
    static void pa(String arrayName, int[][] arr) {
        pl(arrayName+" : ");
        for(int i=0;i<arr.length;++i) {
            for(int o : arr[i])
                p(o);
            pl();
        }
    }
    static void pa(String arrayName, long[][] arr) {
        pl(arrayName+" : ");
        for(int i=0;i<arr.length;++i) {
            for(long o : arr[i])
                p(o);
            pl();
        }
    }
    static void pa(String arrayName, char[][] arr) {
        pl(arrayName+" : ");
        for(int i=0;i<arr.length;++i) {
            for(char o : arr[i])
                p(o);
            pl();
        }
    }
    static void pa(String arrayName, double[][] arr) {
        pl(arrayName+" : ");
        for(int i=0;i<arr.length;++i) {
            for(double o : arr[i])
                p(o);
            pl();
        }
    }
    static class FastReader {
        final private int BUFFER_SIZE = 1 << 16;
        private DataInputStream din;
        private byte[] buffer;
        private int bufferPointer, bytesRead;

        public FastReader() {
            din = new DataInputStream(System.in);
            buffer = new byte[BUFFER_SIZE];
            bufferPointer = bytesRead = 0;
        }

        public FastReader(String file_name) throws IOException {
            din = new DataInputStream(new FileInputStream(file_name));
            buffer = new byte[BUFFER_SIZE];
            bufferPointer = bytesRead = 0;
        }

        public String readLine() throws IOException {
            byte[] buf = new byte[1000000];
            int cnt = 0, c;
            while ((c = read()) != -1) {
                if (c == '\n') break;
                buf[cnt++] = (byte) c;
            }
            return new String(buf, 0, cnt);
        }

        public int nextInt() throws IOException {
            int ret = 0;
            byte c = read();
            while (c <= ' ') c = read();
            boolean neg = (c == '-');
            if (neg) c = read();
            do {
                ret = ret * 10 + c - '0';
            } while ((c = read()) >= '0' && c <= '9');
            if (neg) return -ret;
            return ret;
        }

        public long nextLong() throws IOException {
            long ret = 0;
            byte c = read();
            while (c <= ' ') c = read();
            boolean neg = (c == '-');
            if (neg) c = read();
            do {
                ret = ret * 10 + c - '0';
            } while ((c = read()) >= '0' && c <= '9');
            if (neg) return -ret;
            return ret;
        }

        public double nextDouble() throws IOException {
            double ret = 0, div = 1;
            byte c = read();
            while (c <= ' ') c = read();
            boolean neg = (c == '-');
            if (neg) c = read();
            do {
                ret = ret * 10 + c - '0';
            } while ((c = read()) >= '0' && c <= '9');
            if (c == '.') while ((c = read()) >= '0' && c <= '9') ret += (c - '0') / (div *= 10);
            if (neg) return -ret;
            return ret;
        }

        private void fillBuffer() throws IOException {
            bytesRead = din.read(buffer, bufferPointer = 0, BUFFER_SIZE);
            if (bytesRead == -1) buffer[0] = -1;
        }

        private byte read() throws IOException {
            if (bufferPointer == bytesRead) fillBuffer();
            return buffer[bufferPointer++];
        }

        public void close() throws IOException {
            if (din == null) return;
            din.close();
        }
    }
}