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.
import java.io.*;
import java.util.*;
import java.util.function.BinaryOperator;


public class Main {
    private final static long mod = 1000000007;

    private final static int MAXN = 1000001;

    private static long power(long x, long y, long m) {
        long temp;
        if (y == 0)
            return 1;
        temp = power(x, y / 2, m);
        temp = (temp * temp) % m;
        if (y % 2 == 0)
            return temp;
        else
            return ((x % m) * temp) % m;
    }

    private static long power(long x, long y) {
        return power(x, y, mod);
    }

    private static long gcd(long a, long b) {
        if (b == 0) return a;
        return gcd(b, a % b);
    }

    static int nextPowerOf2(int a) {
        return 1 << nextLog2(a);
    }

    static int nextLog2(int a) {
        return (a == 0 ? 0 : 32 - Integer.numberOfLeadingZeros(a - 1));
    }

    private static long modInverse(long a, long m) {
        long m0 = m;
        long y = 0, x = 1;
        if (m == 1)
            return 0;
        while (a > 1) {
            long q = a / m;
            long t = m;
            m = a % m;
            a = t;
            t = y;
            y = x - q * y;
            x = t;
        }
        if (x < 0)
            x += m0;
        return x;
    }

    private static int[] getLogArr(int n) {
        int arr[] = new int[n + 1];
        for (int i = 1; i < n + 1; i++) {
            arr[i] = (int) (Math.log(i) / Math.log(2) + 1e-10);
        }
        return arr;
    }

    private static int log[] = getLogArr(MAXN);

    private static int getLRSpt(int st[][], int L, int R, BinaryOperator<Integer> binaryOperator) {
        int j = log[R - L + 1];
        return binaryOperator.apply(st[L][j], st[R - (1 << j) + 1][j]);
    }

    private static int[][] getSparseTable(int array[], BinaryOperator<Integer> binaryOperator) {
        int k = log[array.length + 1] + 1;
        int st[][] = new int[array.length + 1][k + 1];

        for (int i = 0; i < array.length; i++)
            st[i][0] = array[i];

        for (int j = 1; j <= k; j++) {
            for (int i = 0; i + (1 << j) <= array.length; i++) {
                st[i][j] = binaryOperator.apply(st[i][j - 1], st[i + (1 << (j - 1))][j - 1]);
            }
        }
        return st;
    }

    static class Subset {
        int parent;
        int rank;

        @Override
        public String toString() {
            return "" + parent;
        }
    }

    static int find(Subset[] Subsets, int i) {
        if (Subsets[i].parent != i)
            Subsets[i].parent = find(Subsets, Subsets[i].parent);
        return Subsets[i].parent;
    }

    static void union(Subset[] Subsets, int x, int y) {
        int xroot = find(Subsets, x);
        int yroot = find(Subsets, y);

        if (Subsets[xroot].rank < Subsets[yroot].rank)
            Subsets[xroot].parent = yroot;
        else if (Subsets[yroot].rank < Subsets[xroot].rank)
            Subsets[yroot].parent = xroot;
        else {
            Subsets[xroot].parent = yroot;
            Subsets[yroot].rank++;
        }
    }


    private static int maxx(Integer... a) {
        return Collections.max(Arrays.asList(a));
    }

    private static int minn(Integer... a) {
        return Collections.min(Arrays.asList(a));
    }


    private static long maxx(Long... a) {
        return Collections.max(Arrays.asList(a));
    }

    private static long minn(Long... a) {
        return Collections.min(Arrays.asList(a));
    }

    private static class Pair<T, U> implements Comparable<Pair<T, U>> {
        T a;
        U b;

        public Pair(T a, U b) {
            this.a = a;
            this.b = b;
        }

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

        @Override
        public int hashCode() {
            return Objects.hash(a, b);
        }

        @Override
        public String toString() {
            return "(" + a +
                    "," + b +
                    ')';
        }

        @Override
        public int compareTo(Pair<T, U> o) {
            return (int) (this.a.equals(o.a) ?
                    this.b.equals(o.b) ? 0 :
                            ((Integer) this.b - (Integer) o.b) / Math.abs((Integer) this.b - (Integer) o.b) :
                    ((Integer) this.a - (Integer) o.a) / Math.abs((Integer) this.a - (Integer) o.a));
        }
    }



    public static int upperBound(List<Integer> list, int value) {
        int low = 0;
        int high = list.size();
        while (low < high) {
            final int mid = (low + high) / 2;
            if (value >= list.get(mid)) {
                low = mid + 1;
            } else {
                high = mid;
            }
        }
        return low;
    }


    private static int[] getLPSArray(String pattern) {
        int i, j, n = pattern.length();
        int[] lps = new int[pattern.length()];
        lps[0] = 0;
        for (i = 1, j = 0; i < n; ) {
            if (pattern.charAt(i) == pattern.charAt(j)) {
                lps[i++] = ++j;
            } else if (j > 0) {
                j = lps[j - 1];
            } else {
                lps[i++] = 0;
            }
        }
        return lps;
    }

    private static List<Integer> findPattern(String text, String pattern) {
        List<Integer> matchedIndexes = new ArrayList<>();
        if (pattern.length() == 0) {
            return matchedIndexes;
        }
        int[] lps = getLPSArray(pattern);
        int i = 0, j = 0, n = text.length(), m = pattern.length();
        while (i < n) {
            if (text.charAt(i) == pattern.charAt(j)) {
                i++;
                j++;
            }
            if (j == m) {
                matchedIndexes.add(i - j);
                j = lps[j - 1];
            }
            if (i < n && text.charAt(i) != pattern.charAt(j)) {
                if (j > 0) {
                    j = lps[j - 1];
                } else {
                    i++;
                }
            }
        }
        return matchedIndexes;
    }

    private static Set<Long> getDivisors(long n) {
        Set<Long> divisors = new HashSet<>();
        divisors.add(1L);
        divisors.add(n);
        for (long i = 2; i <= Math.sqrt(n); i++) {
            if (n % i == 0) {
                divisors.add(i);
                divisors.add(n / i);
            }
        }
        return divisors;
    }

    private static long getLCM(long a, long b) {
        return (Math.max(a, b) / gcd(a, b)) * Math.min(a, b);
    }

    static long fac[] = new long[2000005];
    static long ifac[] = new long[2000005];

    private static void preCompute(int n) {
        fac = new long[n + 1];
        ifac = new long[n + 1];
        fac[0] = ifac[0] = fac[1] = ifac[1] = 1;
        int i;
        for (i = 2; i < n + 1; i++) {
            fac[i] = (i * fac[i - 1]) % mod;
            ifac[i] = (power(i, mod - 2) * ifac[i - 1]) % mod;
        }
    }

    private static long C(int n, int r) {
        if (n < 0 || r < 0) return 1;
        if (r > n) return 1;
        return (fac[n] * ((ifac[r] * ifac[n - r]) % mod)) % mod;
    }



    static long getSum(long BITree[], int index)
    {
        long sum = 0;
        index = index + 1;
        while(index>0)
        {
            index -= index & (-index);
        }
        return sum;
    }

    public static void updateBIT(long BITree[], int index, long val)
    {
        index = index + 1;
        while(index <= BITree.length-1) {
            BITree[index] += val;
            index += index & (-index);
        }
    }
    long[] constructBITree(int arr[], int m)
    {
        int n=arr.length;
        long BITree[] = new long[m+1];
        for(int i=1; i<=n; i++)
            BITree[i] = 0;
        for(int i = 0; i < n; i++)
            updateBIT(BITree, i, arr[i]);
        return BITree;
    }


    private static int upperBound(int a[], int l, int r, int x) {
        if(l>r)return -1;
        if(l==r){
            if(a[l]<=x) {
                return -1;
            }
            else{
                return a[l];
            }
        }
        int m=(l+r)/2;
        if(a[m]<=x) {
            return upperBound(a, m+1,r,x);
        }
        else {
            return upperBound(a, l,m,x);
        }
    }


    private static long getCntOdd(long x, long y)
    {
        long p2 = 1;
        long ans = 0;
        while (p2 * x <= y)
        {
            long hi = Math.min (y, p2 * (x + 1) - 1);
            ans += hi - p2 * x + 1;
            p2 *= 2;
        }
        return ans;
    }

    private static long getCnt(long x, long y)
    {
        long ans=getCntOdd(x,y);
        if(x%2==0) ans+=getCntOdd(x+1,y);
        //System.out.println(ans);
        return ans;
    }



    public static void main(String[] args) throws Exception {

        long START_TIME = System.currentTimeMillis();
        try (FastReader in = new FastReader();
             FastWriter out = new FastWriter()) {

            int t, i, j, n,f, k, m, ti, tidx, gm, q, g;
            //for (t = in.nextInt(), tidx = 1; tidx <= t; tidx++)
            {
                long w,x, y = 0, z = 0, sum = 0, bhc = 0, ans = 0,l,r;
                //out.print(String.format("Case #%d: ", tidx));
                x=in.nextLong();
                y=in.nextLong();
                long res = 1;

                long cn = x;
                while (cn>0)
                {
                    for ( i = 0; i <= 10; i++)
                    {
                        if (i >= cn) continue;
                        if (getCnt(cn - i, x) >= y)
                        {
                            res = Math.max (res, cn - i);
                        }
                    }
                    cn /= 2;
                }
                out.println(res);

            }
            if (args.length > 0 && "ex_time".equals(args[0])) {
                out.print("\nTime taken: ");
                out.println(System.currentTimeMillis() - START_TIME);
            }
            out.commit();
        } catch (Exception e) {
            e.printStackTrace();
        }


    }


    public static class FastReader implements Closeable {
        private BufferedReader br = new BufferedReader(new InputStreamReader(System.in));
        private StringTokenizer st;

        String next() {
            while (st == null || !st.hasMoreElements()) {
                try {
                    st = new StringTokenizer(br.readLine());
                } catch (Exception 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;
        }

        int[] nextIntArr(int n) {
            int[] arr = new int[n];
            for (int i = 0; i < n; i++) {
                arr[i] = nextInt();
            }
            return arr;
        }

        int[] nextIntegerArr(int n) {
            int[] arr = new int[n];
            for (int i = 0; i < n; i++) {
                arr[i] = nextInt();
            }
            return arr;
        }

        double[] nextDoubleArr(int n) {
            double[] arr = new double[n];
            for (int i = 0; i < n; i++) {
                arr[i] = nextDouble();
            }
            return arr;
        }

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

        String[] nextStrArr(int n) {
            String[] arr = new String[n];
            for (int i = 0; i < n; i++) {
                arr[i] = next();
            }
            return arr;
        }


        long[][] nextLongArr2(int n, int m) {
            long[][] arr = new long[n][m];
            for (int i = 0; i < n; i++) {
                arr[i] = nextLongArr(m);
            }
            return arr;
        }

        @Override
        public void close() throws IOException {
            br.close();
        }
    }


    public static class FastWriter implements Closeable {
        BufferedWriter bw;
        StringBuilder sb = new StringBuilder();
        List<String> list = new ArrayList<>();
        Set<String> set = new HashSet<>();

        public FastWriter() {
            bw = new BufferedWriter(new OutputStreamWriter(System.out));
        }

        <T> void commit() throws IOException {
            bw.write(sb.toString());
            bw.flush();
            sb = new StringBuilder();
        }

        public <T> void print(T obj) throws IOException {
            sb.append(obj.toString());
        }

        public void println() throws IOException {
            print("\n");
        }

        public <T> void println(T obj) throws IOException {
            print(obj.toString() + "\n");
        }

        <T> void printArrLn(T[] arr) throws IOException {
            for (int i = 0; i < arr.length - 1; i++) {
                print(arr[i] + " ");
            }
            println(arr[arr.length - 1]);
        }

        <T> void printArr2(T[][] arr) throws IOException {
            for (int j = 0; j < arr.length; j++) {
                for (int i = 0; i < arr[j].length - 1; i++) {
                    print(arr[j][i] + " ");
                }
                println(arr[j][arr.length - 1]);
            }
        }

        <T> void printColl(Collection<T> coll) throws IOException {
            for (T e : coll) {
                print(e + " ");
            }
            println();
        }

        void printCharN(char c, int n) throws IOException {
            for (int i = 0; i < n; i++) {
                print(c);
            }
        }

        void printIntArr2(int[][] arr) throws IOException {
            for (int j = 0; j < arr.length; j++) {
                for (int i = 0; i < arr[j].length - 1; i++) {
                    print(arr[j][i] + " ");
                }
                println(arr[j][arr.length - 1]);
            }
        }

        @Override
        public void close() throws IOException {
            bw.close();
        }

    }

}