Maximum XOR Pair Problem

Given N integers A₁, A₂, …, A_N, choose two of them to compute the XOR (exclusive‑or) value. What is the maximum possible result?

Input Format

• The first line contains an integer N.
• The second line contains N integers A₁ … A_N.

Output Format
Output a single integer — the maximum XOR value obtained from two chosen numbers.

Data Range
1 ≤ N ≤ 10⁵
0 ≤ A_i < 2³¹

Sample Input

3
1 2 3

Sample Output

3