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.*;


public class Main {

	static class PairComparator implements Comparator<Pair> {
		@Override
		public int compare(Pair x, Pair y) {
			if (x.val < y.val)
				return -1;
			if (x.val > y.val)
				return 1;
			if (x.val == y.val) {
				if (x.ind < y.ind)
					return -1;
				if (x.ind > y.ind)
					return 1;
			}
			return 0;
		}
	}

	static class Pair {
		int ind, val;

		Pair(int i, int v) {
			ind = i;
			val = v;
		}
	}


	static int calcMex(int[] arr){
		HashSet<Integer > hs = new HashSet<>();
		for (int i=0;i<arr.length;i++){
			hs.add(arr[i]);
		}
		for (int i=0;i<arr.length;i++){
			if (!hs.contains(i))return i;
		}
		return arr.length;
	}


	static void func() throws Exception {
		int n = sc.nextInt();
		long[] arr = sc.longArr(n);
		long val = arr[0];
		if (n==2)val = arr[0] | arr[1];
		for (int i=0;i<n;i++){
			for (int j = 0; j  < n; j++) {
				if (i==j)continue;
				for (int k=0;k<n;k++){
					if (i==k || j==k)continue;
					val = Math.max(val, arr[i] | arr[j] | arr[k]);
				}
				
			}
		}
		pw.println(val);
	
		


		
	}

	/*
	 
	 * */
	static PrintWriter pw;
	static MScanner sc;

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

		pw = new PrintWriter(System.out);
		sc = new MScanner(System.in);

		int tests = 1;
//		tests =sc.nextInt(); //comment this line
		while (tests-- > 0) {
			func();
			pw.flush();
		}

	}

	static class MScanner {
		StringTokenizer st;
		BufferedReader br;

		public MScanner(InputStream system) {
			br = new BufferedReader(new InputStreamReader(system));
		}

		public MScanner(String file) throws Exception {
			br = new BufferedReader(new FileReader(file));
		}

		public String next() throws IOException {
			while (st == null || !st.hasMoreTokens())
				st = new StringTokenizer(br.readLine());
			return st.nextToken();
		}

		public int[] intArr(int n) throws IOException {
			int[] in = new int[n];
			for (int i = 0; i < n; i++)
				in[i] = nextInt();
			return in;
		}

		public long[] longArr(int n) throws IOException {
			long[] in = new long[n];
			for (int i = 0; i < n; i++)
				in[i] = nextLong();
			return in;
		}

		public int[] intSortedArr(int n) throws IOException {
			int[] in = new int[n];
			for (int i = 0; i < n; i++)
				in[i] = nextInt();
			shuffle(in);
			Arrays.sort(in);
			return in;
		}

		public long[] longSortedArr(int n) throws IOException {
			long[] in = new long[n];
			for (int i = 0; i < n; i++)
				in[i] = nextLong();
			shuffle(in);
			Arrays.sort(in);
			return in;
		}

		public Integer[] IntegerArr(int n) throws IOException {
			Integer[] in = new Integer[n];
			for (int i = 0; i < n; i++)
				in[i] = nextInt();
			return in;
		}

		public Long[] LongArr(int n) throws IOException {
			Long[] in = new Long[n];
			for (int i = 0; i < n; i++)
				in[i] = nextLong();
			return in;
		}

		public String nextLine() throws IOException {
			return br.readLine();
		}

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

		public double nextDouble() throws IOException {
			return Double.parseDouble(next());
		}

		public char nextChar() throws IOException {
			return next().charAt(0);
		}

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

		public boolean ready() throws IOException {
			return br.ready();
		}

		public void waitForInput() throws InterruptedException {
			Thread.sleep(3000);
		}
	}

	static void shuffle(int[] in) {
		for (int i = 0; i < in.length; i++) {
			int idx = (int) (Math.random() * (i + 1));
			int tmp = in[i];
			in[i] = in[idx];
			in[idx] = tmp;
		}
	}

	static void shuffle(long[] in) {
		for (int i = 0; i < in.length; i++) {
			int idx = (int) (Math.random() * (i + 1));
			long tmp = in[i];
			in[i] = in[idx];
			in[idx] = tmp;
		}
	}
}
