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.BufferedReader;
import java.io.IOException;
import java.io.InputStreamReader;
import java.io.PrintWriter;
import java.util.*;

public class d extends PrintWriter{
    static BufferedReader s = new BufferedReader(new InputStreamReader(System.in));
    // static Scanner s=new Scanner(System.in);
    d() { super(System.out); }
    public static void main(String[] args) throws IOException{
        d d1=new d();d1.main();d1.flush();
    }void main() throws IOException {
        StringBuilder sb = new StringBuilder();
        PrintWriter out = new PrintWriter(System.out);
         String[] s1=s();
         int n=i(s1[0]);
         String[] s2=s();
         long[] a=new long[n];
         for(int i=0;i<n;i++){
             a[i]=l(s2[i]);
         }
         Arrays.sort(a);
         int [] max=new int[62];
         long mb=-1;
         for(long j=61;j>=0;j--){
             int c0=0;
             int i;
             for( i=n-1;i>=0;i--){
                  if((a[i]&(1L<<j))==0){
                      c0++;
                  }else{
                      if(mb==-1) mb=j;
                  }
                  if(c0==3) break;
          }
           max[(int)j]=i+1;
       }
      int min=Integer.MAX_VALUE;
      long ans=0;long fans=0;
     if(n==1) fans=a[0];if(n==2) fans=a[0]|a[1]; 
     for(int i=0;i<n;i++){
         for(int j=i+1;j<n;j++){
             for(int k=j+1;k<n;k++){
                 fans=Math.max(fans,a[i]|a[j]|a[k]);
             }
         }
     }
     
        System.out.println((long)fans);
        }
    static long  powerwithoutmod(long x, int y) {
        long  temp;
        if( y == 0)
            return 1;
        temp = powerwithoutmod(x, y/2);
        if (y%2 == 0)
            return temp*temp;
        else
        {
            if(y > 0)
                return x * temp * temp;
            else
                return (temp * temp) / x;
        }
    }
    static String[] s() throws IOException {

        return s.readLine().trim().split("\\s+");
    }

    static int i(String ss) {
        return Integer.parseInt(ss);
    }
    static long l(String ss) {
        return Long.parseLong(ss);
    }
}
class node implements Comparator<node>{
    int ver,val;
    public node(){}
    public node(int ver,int val) {
        this.ver=ver;this.val=val;
    }public int compare(node n1,node n2){
       return n1.val-n2.val;
    }
}

class Student12 {
    int  l;long r;
    public Student12(int l, long r) {
        this.l = l;
        this.r = r;
    }

    public String toString()
    {
        return this.l+" ";
    }
}
class Sortbyroll12 implements Comparator<Student12> {

    public int compare(Student12 a, Student12 b){
        if(a.r<b.r) return 1;else if(a.r==b.r) return 0;else return -1;// a.r-b.r;
      /*  if(b.r<a.r) return -1;
        else if(b.r==a.r) return 0;
        return 1;*/

        //   return b.r-a.r;
       /*
       if(b.l<a.l) return -1;
       else if(b.l==a.l) {
           return b.r-a.r;
       }
       return 1;*/
        //        return b.r- a.r;
        //        return (int) a.l-(int) b.l;
         /*   if(a.r<b.r) return -1;
            else if(a.r==b.r){
                if(a.r==b.r){
                    return 0;
                }
                if(a.r<b.r) return -1;
                return 1;}
            return 1;  */}
}
class Node1 implements Comparator<Node1>{
    int node;long val;
    public  Node1(){}
    public  Node1(int node,long val){
        this.node=node;this.val=val;
    }
    @Override
    public int compare(Node1 a,Node1 b){
        if(a.val<b.val) return -1;
        if(a.val==b.val) return 0;
        {
            return 1;
        }
    }
}
