NIT, the cleaver, is new in town! Thousands of people line up to orz him. To keep his orzers entertained, NIT decided to let them solve the following problem related to $\operatorname{or} z$. Can you solve this problem too?
You are given a 1-indexed array of $n$ integers, $a$, and an integer $z$. You can do the following operation any number (possibly zero) of times:
- Select a positive integer
$i$such that$1\le i\le n$. Then, simutaneously set$a_i$to$(a_i\operatorname{or} z)$and set$z$to$(a_i\operatorname{and} z)$. In other words, let$x$and$y$respectively be the current values of$a_i$and$z$. Then set$a_i$to$(x\operatorname{or}y)$and set$z$to$(x\operatorname{and}y)$.
Here $\operatorname{or}$ and $\operatorname{and}$ denote the bitwise operations OR and AND respectively.
Find the maximum possible value of the maximum value in $a$ after any number (possibly zero) of operations.
Input
Each test contains multiple test cases. The first line contains the number of test cases $t$ ($1 \le t \le 100$). Description of the test cases follows.
The first line of each test case contains two integers $n$ and $z$ ($1\le n\le 2000$, $0\le z \lt 2^{30}$).
The second line of each test case contains $n$ integers $a_1$,$a_2$,$\ldots$,$a_n$ ($0\le a_i \lt 2^{30}$).
It is guaranteed that the sum of $n$ over all test cases does not exceed $10^4$.
Output
For each test case, print one integer — the answer to the problem.
Note
In the first test case of the sample, one optimal sequence of operations is:
- Do the operation with
$i=1$. Now$a_1$becomes$(3\operatorname{or}3)=3$and$z$becomes$(3\operatorname{and}3)=3$. - Do the operation with
$i=2$. Now$a_2$becomes$(4\operatorname{or}3)=7$and$z$becomes$(4\operatorname{and}3)=0$. - Do the operation with
$i=1$. Now$a_1$becomes$(3\operatorname{or}0)=3$and$z$becomes$(3\operatorname{and}0)=0$.
After these operations, the sequence $a$ becomes $[3,7]$, and the maximum value in it is $7$. We can prove that the maximum value in $a$ can never exceed $7$, so the answer is $7$.
In the fourth test case of the sample, one optimal sequence of operations is:
- Do the operation with
$i=1$. Now$a_1$becomes$(7\operatorname{or}7)=7$and$z$becomes$(7\operatorname{and}7)=7$. - Do the operation with
$i=3$. Now$a_3$becomes$(30\operatorname{or}7)=31$and$z$becomes$(30\operatorname{and}7)=6$. - Do the operation with
$i=5$. Now$a_5$becomes$(27\operatorname{or}6)=31$and$z$becomes$(27\operatorname{and}6)=2$.
样例
5
2 3
3 4
5 5
0 2 4 6 8
1 9
10
5 7
7 15 30 29 27
3 39548743
10293834 10284344 13635445
7
13
11
31
48234367
题面与样例版权归 Codeforces 及出题人所有;中文翻译由 AI 生成(CI 管线),如有出入请以原文为准。