Ridhiman challenged Ashish to find the maximum valued subsequence of an array a of size n consisting of positive integers. 

The value of a non-empty subsequence of k elements of a is defined as ∑ 2^i over all integers i ≥ 0 such that at least max(1, k - 2) elements of the subsequence have the i-th bit set in their binary representation (value x has the i-th bit set in its binary representation if ⌊ (x)/(2^i) ⌋ mod 2 is equal to 1). 

Recall that b is a subsequence of a, if b can be obtained by deleting some(possibly zero) elements from a.

Help Ashish find the maximum value he can get by choosing some subsequence of a.

Input

The first line of the input consists of a single integer n (1 ≤ n ≤ 500) — the size of a.

The next line consists of n space-separated integers — the elements of the array (1 ≤ a_i ≤ 10^{18}).

Output

Print a single integer — the maximum value Ashish can get by choosing some subsequence of a.

Examples

Input


3
2 1 3


Output


3

Input


3
3 1 4


Output


7

Input


1
1


Output


1

Input


4
7 7 1 1


Output


7

Note

For the first test case, Ashish can pick the subsequence \{{2, 3}\} of size 2. The binary representation of 2 is 10 and that of 3 is 11. Since max(k - 2, 1) is equal to 1, the value of the subsequence is 2^0 + 2^1 (both 2 and 3 have 1-st bit set in their binary representation and 3 has 0-th bit set in its binary representation). Note that he could also pick the subsequence \{{3\}} or \{{2, 1, 3\}}.

For the second test case, Ashish can pick the subsequence \{{3, 4\}} with value 7.

For the third test case, Ashish can pick the subsequence \{{1\}} with value 1.

For the fourth test case, Ashish can pick the subsequence \{{7, 7\}} with value 7.
import java.io.BufferedOutputStream;
import java.io.BufferedReader;
import java.io.ByteArrayInputStream;
import java.io.ByteArrayOutputStream;
import java.io.DataInputStream;
import java.io.FileInputStream;
import java.io.FileReader;
import java.io.IOException;
import java.io.InputStreamReader;
import java.io.ObjectInputStream;
import java.io.ObjectOutputStream;
import java.io.PrintWriter;
import java.util.Arrays;
import java.util.HashMap;
import java.util.HashSet;
import java.util.PriorityQueue;
import java.util.TreeSet;
import java.util.Scanner;
import java.util.StringTokenizer;
import java.util.Vector;

import static java.util.Collections.*;
import static java.lang.Math.*;
import static java.util.Arrays.*;

public class cf {

    private static final int MOD = (int) (1e9 + 7), MOD_FFT = 998244353;
    private static Scanner in;
    private static final Reader r = new Reader();
    private static final PrintWriter out = new PrintWriter(new BufferedOutputStream(System.out));
    private static final boolean thread = false, FASTIO = true;

    public static void main(final String[] args) throws Exception {
        if (!thread) {
            final int testcases = HAS_TEST_CASES ? ni() : 1;
            for (int i = 1; i <= testcases; i++) {
                // out.print("Case #" + (i + 1) + ": ");
                try {
                    solve();
                } catch (final Exception e) {
                    pn(e.getMessage());
                    pni("idk Exception");
                    e.printStackTrace(System.err);
                }
            }
            out.flush();
        }
    }

    static final boolean HAS_TEST_CASES = false;
    static final int SCAN_LINE_LENGTH = 1000002;

    static int n, a[], b[], e[][];

    private static Vector<Integer> adj[], v = new Vector<>();

    static void solve() throws Exception {
        int n = ni();
        long a[] = new long[n];
        for (int i = 0; i < a.length; i++) {
            a[i]=nl();
        }
        long ans = 0;
        for (int i = 0; i < n; ++i) {
          for (int j = 0; j < n; ++j) {
            for (int k = 0; k < n; ++k) {
              ans = max(ans, a[i] | a[j] | a[k]);
            }
          }
        }
        pn(ans);
    }

    private static void swap(final int i, final int j) {
        final int temp = a[i];
        a[i] = a[j];
        a[j] = temp;
    }

    private static void swapb(final int i, final int j) {
        final int temp = b[i];
        b[i] = b[j];
        b[j] = temp;
    }

    private static boolean isMulOverflow(final long A, final long B) {
        if (A == 0 || B == 0)
            return false;
        final long result = A * B;
        if (A == result / B)
            return true;
        return false;
    }

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

    private static class Pair<T, E> implements Comparable<Pair<T, E>> {
        T fir;
        E snd;

        Pair() {
        }

        Pair(final T x, final E y) {
            this.fir = x;
            this.snd = y;
        }

        @Override
        @SuppressWarnings("unchecked")
        public int compareTo(final Pair<T, E> o) {
            final int c = ((Comparable<T>) fir).compareTo(o.fir);
            return c != 0 ? c : ((Comparable<E>) snd).compareTo(o.snd);
        }

    }

    private static class pi implements Comparable<pi> {
        int fir, snd;

        pi() {
        }

        pi(final int a, final int b) {
            fir = a;
            snd = b;
        }

        public int compareTo(final pi o) {
            return fir == o.fir ? snd - o.snd : fir - o.fir;
        }

    }

    private static <T> void checkV(final Vector<T> adj[], final int i) {
        adj[i] = adj[i] == null ? new Vector<>() : adj[i];
    }

    private static int[] na(final int n) throws Exception {
        final int[] a = new int[n];
        for (int i = 0; i < n; i++) {
            a[i] = ni();
        }
        return a;
    }

    private static int[] na1(final int n) throws Exception {
        final int[] a = new int[n + 1];
        for (int i = 1; i < a.length; i++) {
            a[i] = ni();
        }
        return a;
    }

    private static String n() throws IOException {
        return FASTIO ? r.readToken() : in.next();
    }

    private static String nln() throws IOException {
        return FASTIO ? r.readLine() : in.nextLine();
    }

    private static int ni() throws IOException {
        return FASTIO ? r.nextInt() : in.nextInt();
    }

    private static long nl() throws IOException {
        return FASTIO ? r.nextLong() : in.nextLong();
    }

    private static double nd() throws IOException {
        return FASTIO ? r.nextDouble() : in.nextDouble();
    }

    private static void p(final Object o) {
        out.print(o);
    }

    private static void pn(final Object o) {
        out.println(o);
    }

    private static void pn() {
        out.println("");
    }

    private static void pni(final Object o) {
        out.println(o);
        out.flush();
    }

    private static class Reader {
        private final int BUFFER_SIZE = 1 << 19;
        private final DataInputStream din;
        private final byte[] buffer;
        private int bufferPointer, bytesRead;
        private StringTokenizer st;
        private final BufferedReader br;

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

        public Reader(final String file_name) throws IOException {
            din = new DataInputStream(new FileInputStream(file_name));
            br = new BufferedReader(new FileReader(file_name));
            buffer = new byte[BUFFER_SIZE];
            bufferPointer = bytesRead = 0;
        }

        public String next() throws Exception {
            while (st == null || !st.hasMoreElements()) {
                try {
                    st = new StringTokenizer(br.readLine());
                } catch (final IOException e) {
                    throw new Exception(e.toString());
                }
            }
            return st.nextToken();
        }

        public String nextLine() throws Exception {
            String str = "";
            try {
                str = br.readLine();
            } catch (final IOException e) {
                throw new Exception(e.toString());
            }
            return str;
        }

        final byte[] buf = new byte[SCAN_LINE_LENGTH];

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

        public String readToken() throws IOException {
            int cnt = 0;
            int c;
            while ((c = read()) != -1) {
                if (c == '\n' || c == ' ')
                    if (cnt == 0)
                        continue;
                    else
                        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();
            final 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();
            final 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();
            final 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();
        }
    }

    static {
        if (!FASTIO)
            in = new Scanner(new BufferedReader(new InputStreamReader(System.in)));
        if (thread)
            new Thread(null, new Runnable() {
                @Override
                public void run() {
                    try {
                        final int testcases = HAS_TEST_CASES ? ni() : 1;
                        for (int i = 1; i <= testcases; i++) {
                            // out.print("Case #" + (i + 1) + ": ");
                            try {
                                solve();
                            } catch (final ArrayIndexOutOfBoundsException e) {
                                e.printStackTrace(System.err);
                                System.exit(-1);
                            } catch (final Exception e) {
                                pni("idk Exception in solve");
                                e.printStackTrace(System.err);
                                System.exit(-1);
                            }
                        }
                        out.flush();
                    } catch (final Throwable t) {
                        t.printStackTrace(System.err);
                        System.exit(-1);
                    }
                }
            }, "rec", (1L << 28)).start();
    }

    @SuppressWarnings({ "unchecked" })
    private static <T> T deepCopy(final T old) {
        try {
            return (T) deepCopyObject(old);
        } catch (final IOException | ClassNotFoundException e) {
            e.printStackTrace();
            System.exit(-1);
        }
        return null;
    }

    private static Object deepCopyObject(final Object oldObj) throws IOException, ClassNotFoundException {
        ObjectOutputStream oos = null;
        ObjectInputStream ois = null;
        try {
            final ByteArrayOutputStream bos = new ByteArrayOutputStream(); // A
            oos = new ObjectOutputStream(bos); // B
            // serialize and pass the object
            oos.writeObject(oldObj); // C
            oos.flush(); // D
            final ByteArrayInputStream bin = new ByteArrayInputStream(bos.toByteArray()); // E
            ois = new ObjectInputStream(bin); // F
            // return the new object
            return ois.readObject(); // G
        } catch (final ClassNotFoundException e) {
            pni("Exception in ObjectCloner = " + e);
            throw (e);
        } finally {
            oos.close();
            ois.close();
        }
    }

}