M is alone and he has an array \(a_1, a_2, ..., a_n\). M wants to choose two integers \(i, j\) such that \(i \neq j, 1 \leq i, j \leq n\) and the value \(a_i \& a_j\)(bitwise AND) is maximum.

What is the maximum value M can get?

Input

First line contains only \(n\), legnth of array.

Second line contains the array elements \(a_1, a_2, ..., a_n\)separated by space.

\(1 \leq n \leq 3 \times 10^5\)

\(1 \leq a_i \leq 10^9\)

Output

The only line of output contains an integer, maximum value value that M can get.