题目描述
Sakurako has prepared a task for you:
She gives you an array of $n$ integers and allows you to choose $i$ and $j$ such that $i \neq j$ and $a_i \ge a_j$, and then assign $a_i = a_i - a_j$ or $a_i = a_i + a_j$. You can perform this operation any number of times for any $i$ and $j$, as long as they satisfy the conditions.
Sakurako asks you what is the maximum possible value of $mex_k$$^{\text{∗}}$ of the array after any number of operations.
Input
The first line contains a single integer $t$ ($1\le t\le 10^4$) — the number of test cases.
The first line of each test case contains two integers $n$ and $k$ ($1\le n\le 2\cdot 10^5,1\le k\le 10^9$) — the number of elements in the array and the value $k$ for $mex_k$.
The second line of each test case contains $n$ integers $a_1, a_2, \dots,a_n$ ($1\le a_i\le 10^9$) — the elements of the array.
It is guaranteed that the sum of $n$ across all test cases does not exceed $2\cdot 10^5$.
Output
For each test case, output the maximum $mex_k$ that can be achieved through the operations.
输入格式
见题面 Input 部分
输出格式
见题面 Output 部分