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.
/*
If you want to aim high, aim high
Don't let that studying and grades consume you
Just live life young
******************************
What do you think? What do you think?
1st on Billboard, what do you think of it
Next is a Grammy, what do you think of it
However you think, I’m sorry, but shit, I have no fucking interest
*******************************
Higher, higher, even higher, to the point you won’t even be able to see me
https://www.a2oj.com/Ladder16.html
*******************************
NEVER DO 300IQ CONTESTS EVER
300IQ AS WRITER = EXTRA NONO
*/
import java.util.*;
import java.io.*;
import java.math.*;

   public class E
   {
      public static void main(String omkar[]) throws Exception
      {
         BufferedReader infile = new BufferedReader(new InputStreamReader(System.in));  
         StringTokenizer st = new StringTokenizer(infile.readLine());
         int N = Integer.parseInt(st.nextToken());
         long[] arr = readArr2(N, infile, st);
         //solve
         long res = arr[0];
         for(long x: arr)
            res = Math.max(res, x);
         for(int i=0; i < N; i++)
            for(int j=i+1; j < N; j++)
            {
               long temp = arr[i]|arr[j];
               res = Math.max(res, temp);
            }
         for(int a=0; a < N; a++)
            for(int b=a+1; b < N; b++)
               for(int c=b+1; c < N; c++)
               {
                  long temp = arr[a]|arr[b];
                  temp |= arr[c];
                  res = Math.max(res, temp);
               }
         System.out.println(res);
      }
      public static long[] readArr2(int N, BufferedReader infile, StringTokenizer st) throws Exception
      {
         long[] arr = new long[N];
         st = new StringTokenizer(infile.readLine());
         for(int i=0; i < N; i++)
            arr[i] = Long.parseLong(st.nextToken());
         return arr;
      }
   }