CF2169A.Alice and Bob

传统题 时间 2000 ms 内存 256 MiB 4 尝试 1 已通过 1 标签

Alice and Bob

Alice and Bob have a bag with nn marbles, with the integer viv_i written on the ii-th marble. They play the following game: first, each player chooses an integer (let's denote the integer chosen by Alice as aa, and the integer chosen by Bob as bb). After that, they start drawing marbles from the bag in any order until the bag is empty. For each ball, the point goes to the one whose chosen integer is closer to the integer on the marble; in case of a tie, Alice gets the point.

For example, if a=10a = 10, b=30b = 30, then

  • for marbles with integers 10,1,7,18,2010, 1, 7, 18, 20, and many others, Alice gets the points (note that she will get a point for the marble 2020);
  • for marble with integer 59,25,30,2159, 25, 30, 21, and many others, Bob gets the points.

Bob has managed to find out in advance which integer Alice will choose. Help him to choose his integer in such a way as to maximize the number of points he receives.

Input

The first line contains a single integer tt (1t1041 \le t \le 10^4) — the number of test cases.

Each test case consists of two lines:

  • The first line contains two integers nn and aa (1n31051 \le n \le 3 \cdot 10^5; 1a1091 \le a \le 10^9) — the number of marbles in the bag and the number chosen by Alice, respectively.
  • The second line contains nn integers v1,v2,,vnv_1, v_2, \dots, v_n (1v1v2vn1091 \le v_1 \le v_2 \le \dots \le v_n \le 10^9).

Additional constraint on the input: the sum of nn across all test cases does not exceed 31053 \cdot 10^5.

Output

For each test case, output a single integer bb (0b21090 \le b \le 2 \cdot 10^9) that Bob should choose to maximize the number of points he receives. If there are multiple such numbers, you may output any of them.

Note

In the first test case, if Bob chooses 3535, he gets 55 points for marbles 30,40,50,60,7030, 40, 50, 60, 70.

In the third test case, no matter which integer Bob chooses, he gets 00 points.

Samples

3
7 21
10 20 30 40 50 60 70
6 500
200 200 300 500 600 600
2 7
7 7
35
333
1337

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