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.*;
import java.util.*;
import java.util.logging.LoggingPermission;


public class Main implements Runnable {
    int n, m;
    static boolean use_n_tests = false;

    void solve(FastScanner in, PrintWriter out, int testNumber) {
        n = in.nextInt();
        Long[] a = in.nextArrayL2(n);
        Arrays.sort(a);
        long ans = 0;
        if (n < 3) {
            for (int i = 0; i < a.length; i++) {
                ans |= a[i];
            }
        } else {
            for (int i = 0; i < n; i++) {
                for (int j = i + 1; j < n; j++) {
                    for (int k = j + 1; k < n; k++) {
                        ans = Math.max(ans, a[i] | a[j] | a[k]);
                    }
                }
            }
        }
        out.println(ans);
//


//        int ans = 0;
//        long realAns = -1;
//        for (int i = 0; i < a.length; i++) {
//            int mn = Integer.MAX_VALUE;
//            for (int j = 63; j >= 0; j--) {
//                if ((a[i] & (1L << j)) != 0) {
//                    mn = Math.min(mn, bits[j]);
//                }
//            }
//            if (mn > ans) {
//                ans = mn;
//                long real = 0;
//                for (int j = 63; j >= 0; j--) {
//                    if ((a[i] & (1L << j)) != 0) {
//                        real += (1L << j);
//                    }
//                }
//                realAns = real;
//            }
//        }
//        out.println(realAns);
    }

    void add(long a, int[] bits) {
        for (int j = 63; j >= 0; j--) {
            if ((a & (1L << j)) != 0) {
                bits[j]++;
            }
        }
    }

    // ****************************** template code ***********
    static int stack_size = 1 << 27;

    class Coeff {
        long mod;
        long[][] C;
        long[] fact;
        boolean cycleWay = false;

        Coeff(int n, long mod) {
            this.mod = mod;
            fact = new long[n + 1];
            fact[0] = 1;
            for (int i = 1; i <= n; i++) {
                fact[i] = i;
                fact[i] %= mod;
                fact[i] *= fact[i - 1];
                fact[i] %= mod;
            }
        }

        Coeff(int n, int m, long mod) {
            // n > m
            cycleWay = true;
            this.mod = mod;
            C = new long[n + 1][m + 1];
            for (int i = 0; i <= n; i++) {
                for (int j = 0; j <= Math.min(i, m); j++) {
                    if (j == 0 || j == i) {
                        C[i][j] = 1;
                    } else {
                        C[i][j] = C[i - 1][j - 1] + C[i - 1][j];
                        C[i][j] %= mod;
                    }
                }
            }
        }

        public long C(int n, int m) {
            if (cycleWay) {
                return C[n][m];
            }
            return fC(n, m);
        }

        private long fC(int n, int m) {
            return (fact[n] * inv(fact[n - m] * fact[m] % mod)) % mod;
        }

        private long inv(long r) {
            if (r == 1)
                return 1;
            return ((mod - mod / r) * inv(mod % r)) % mod;
        }
    }

    class Pair {
        int first;
        int second;

        public int getFirst() {
            return first;
        }

        public int getSecond() {
            return second;
        }
    }

    class MultisetTree<T> {
        int size = 0;

        TreeMap<T, Integer> mp = new TreeMap<>();

        void add(T x) {
            mp.merge(x, 1, Integer::sum);
            size++;
        }

        void remove(T x) {
            if (mp.containsKey(x)) {
                mp.merge(x, -1, Integer::sum);
                if (mp.get(x) == 0) {
                    mp.remove(x);
                }
                size--;
            }
        }

        boolean contains(T x) {
            return mp.containsKey(x);
        }

        T greatest() {
            return mp.lastKey();
        }

        T smallest() {
            return mp.firstKey();
        }

        int size() {
            return size;
        }

        int diffSize() {
            return mp.size();
        }
    }

    class Multiset<T> {
        int size = 0;

        Map<T, Integer> mp = new HashMap<>();

        void add(T x) {
            mp.merge(x, 1, Integer::sum);
            size++;
        }

        void remove(T x) {
            if (mp.containsKey(x)) {
                mp.merge(x, -1, Integer::sum);
                if (mp.get(x) == 0) {
                    mp.remove(x);
                }
                size--;
            }
        }

        int size() {
            return size;
        }

        int diffSize() {
            return mp.size();
        }
    }

    static class Range {
        int l, r;
        int id;

        public int getL() {
            return l;
        }

        public int getR() {
            return r;
        }

        public Range(int l, int r, int id) {
            this.l = l;
            this.r = r;
            this.id = id;
        }
    }

    static class Array {
        static Range[] readRanges(int n, FastScanner in) {
            Range[] result = new Range[n];
            for (int i = 0; i < n; i++) {
                result[i] = new Range(in.nextInt(), in.nextInt(), i);
            }
            return result;
        }

        static boolean isSorted(Integer[] a) {
            for (int i = 0; i < a.length - 1; i++) {
                if (a[i] > a[i + 1]) {
                    return false;
                }
            }
            return true;
        }

        static public long sum(int[] a) {
            long sum = 0;
            for (int x : a) {
                sum += x;
            }
            return sum;
        }

        static public long sum(long[] a) {
            long sum = 0;
            for (long x : a) {
                sum += x;
            }
            return sum;
        }

        static public long sum(Integer[] a) {
            long sum = 0;
            for (int x : a) {
                sum += x;
            }
            return sum;
        }

        static public int min(Integer[] a) {
            int mn = Integer.MAX_VALUE;
            for (int x : a) {
                mn = Math.min(mn, x);
            }
            return mn;
        }

        static public int min(int[] a) {
            int mn = Integer.MAX_VALUE;
            for (int x : a) {
                mn = Math.min(mn, x);
            }
            return mn;
        }

        static public int max(Integer[] a) {
            int mx = Integer.MIN_VALUE;
            for (int x : a) {
                mx = Math.max(mx, x);
            }
            return mx;
        }

        static public int max(int[] a) {
            int mx = Integer.MIN_VALUE;
            for (int x : a) {
                mx = Math.max(mx, x);
            }
            return mx;
        }

        static public int[] readint(int n, FastScanner in) {
            int[] out = new int[n];
            for (int i = 0; i < out.length; i++) {
                out[i] = in.nextInt();
            }
            return out;
        }
    }

    class Graph {
        List<List<Integer>> graph;

        Graph(int n) {
            create(n);
        }

        void create(int n) {
            List<List<Integer>> graph = new ArrayList<>();
            for (int i = 0; i < n; i++) {
                graph.add(new ArrayList<>());
            }
            this.graph = graph;
        }

        void readBi(int m, FastScanner in) {
            for (int i = 0; i < m; i++) {
                int v = in.nextInt() - 1;
                int u = in.nextInt() - 1;
                graph.get(v).add(u);
                graph.get(u).add(v);
            }
        }
    }

    class FastScanner {
        BufferedReader br;
        StringTokenizer st;

        public FastScanner(InputStream io) {
            br = new BufferedReader(new InputStreamReader(io));
        }

        public String line() {
            String result = "";
            try {
                result = br.readLine();
            } catch (IOException e) {
                e.printStackTrace();
            }
            return result;
        }

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

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

        public int[] nextArray(int n) {
            int[] res = new int[n];
            for (int i = 0; i < n; i++) {
                res[i] = in.nextInt();
            }
            return res;
        }

        public long[] nextArrayL(int n) {
            long[] res = new long[n];
            for (int i = 0; i < n; i++) {
                res[i] = in.nextLong();
            }
            return res;
        }

        public Long[] nextArrayL2(int n) {
            Long[] res = new Long[n];
            for (int i = 0; i < n; i++) {
                res[i] = in.nextLong();
            }
            return res;
        }


        public Integer[] nextArray2(int n) {
            Integer[] res = new Integer[n];
            for (int i = 0; i < n; i++) {
                res[i] = in.nextInt();
            }
            return res;
        }

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

    }

    void run_t_tests() {
        int t = in.nextInt();
        int i = 0;
        while (t-- > 0) {
            solve(in, out, i++);
        }
    }

    void run_one() {
        solve(in, out, -1);
    }

    @Override
    public void run() {
        in = new FastScanner(System.in);
        out = new PrintWriter(System.out);
        if (use_n_tests) {
            run_t_tests();
        } else {
            run_one();
        }
        out.close();
    }

    static FastScanner in;
    static PrintWriter out;

    public static void main(String[] args) throws InterruptedException {
        Thread thread = new Thread(null, new Main(), "", stack_size);
        thread.start();
        thread.join();
    }
}