Bitwise operations

Sometimes we need to perform operations on pairs of binary numbers. If we have two numbers a and b, we might want to have all the bits set to 0s except the ones that are 1 in both a and b (this corresponds to an AND operation). We might otherwise want to have all ones in positions where either a or b have a 1 there (this corresponds to an OR operation).
a
b
a & b (AND)
a | b (OR)
a ^ b (XOR) exclusive OR
binary and decimal representations
binary and decimal representations
1 if both and are 1 and 0 otherwise
1 if either or are 1 and 0 otherwise
1 if bits are different and 0 otherwise
110 (6)
101 (5)
100 (4)
111 (7)
011 (3)
100111 (39)
010100 (20)
100 (4)
110111 (55)
110011 (51)

Challenge

Given n integers, you are asked to find 2 of those that after applying OR to them would result in the largest number.

Input

The first line of the input contains a single integer n (1 ≤ n ≤ 1000).
The next line contains n space-separated integers (1 ≤ ).

Output

The output should contain the largest value you can obtain by applying an OR operation on 2 values from the given numbers.

Examples

Input
Output
5 1 2 3 4 5
7

Explanation

We can obtain 7 by applying OR to:
  • 2 (010) and 5 (101) → 7 (111)
  • 3 (011) and 4 (100) → (111)

Constraints

Time limit: 2.4 seconds

Memory limit: 512 MB

Output limit: 1 MB

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