## 描述

John is a manager of a CPU chip factory, the factory produces lots of chips everyday. To manage large amounts of products, every processor has a serial number. More specifically, the factory produces $n$ chips today, the $i-th$ chip produced this day has a serial number $si$.

At the end of the day, he packages all the chips produced this day, and send it to wholesalers. More specially, he writes a checksum number on the package, this checksum is defined as below: $max_(i,j,k) (s_i + s_j)⊕s_k$

which $i,j,k$ are three different integers between 1 and n. And $⊕$ is symbol of bitwise $XOR$.

Can you help John calculate the checksum number of today?

### 输入

The first line of input contains an integer$T$ indicating the total number of test cases.

The first line of each test case is an integer $n$, indicating the number of chips produced today. The next line has n integers $s1,s2,..,sn$ separated with single space, indicating serial number of each chip.

$1≤T≤1000$
$3≤n≤1000$
$0≤si≤10^9$
There are at most 10 testcases with $n>100$

### 输出

For each test case, please output an integer indicating the checksum number in a line.

### 样例

2
3
1 2 3
3
100 200 300

6
400

#### Note

2015ACM/ICPC亚洲区长春站-重现赛（感谢东北师大）

• 01字典树模板题
• 暴力求解