Problem Description

Given $N$ integers $A_1, A_2, \cdots, A_N$, choose two of them to compute their XOR. What is the maximum possible result?

Input Format

The first line contains an integer $N$. The second line contains $N$ integers $A_1, A_2, \cdots, A_N$.

Output Format

Output one integer representing the answer.

3
1 2 3

3

Hint

For all testdata, $1 \le N \le 10^5$, and it is guaranteed that $0 \le A_i < 2^{31}$.

Translated by ChatGPT 5