Maximum Bitwise AND Score

MCPlayer542 is facing a challenging problem. He has written n different codes, where the i-th code earns a score of g_i. Due to special contest rules, he must make two submissions, and his final score will be the bitwise AND of the scores from the two submissions. Formally, if he submits the i-th and j-th codes, his score will be given by

$$g_i \& g_j$$

Since he is allowed to submit the same code twice, the maximum achievable score is simply

$$\max_{1\le i,j\le n}(g_i \& g_j)=\max_{1\le i\le n}g_i.$$

Your task is to determine the highest score he can achieve given the scores of his submissions.

inputFormat

The input consists of two lines:

• The first line contains an integer n, the number of codes.
• The second line contains n integers, where the i-th integer represents g_i.

outputFormat

Output a single integer representing the maximum possible score that MCPlayer542 can achieve.

sample

1
42

42