Chef Avi likes the number K. Given a list of N integers, help him find the sum of all distinct numbers repeating exactly K times. Each of those numbers should be considered only once in the sum, not K times.

------ Input Format ------

• First line will contain T, number of testcases. Then the testcases follow.
• Each testcase contains two lines:
• The first line contains two space-separated integers N, K.
• The second line contains N space-separated integers.

------ Output Format ------

For each testcase, print the sum of all numbers occurring exactly K times. If there is no such number, print -1 instead.

------ Constraints ------

$1≤ T≤ 10$
$1≤ N≤10,000$
$1 ≤ K ≤ N$
$0 ≤ A_{i} ≤ 10^{9}$

----- Sample Input 1 ------
3
4 1
2 3 4 4
5 3
9 9 1 1 9
2 1
2 2
----- Sample Output 1 ------
5
9
-1
----- explanation 1 ------
Test Case 1: The numbers 2 and 3 occur exactly once. So the answer is 2 + 3 = 5.

Test Case 2: The number 9 occurs exactly three times. So the answer is 9.

Test Case 3: There is no number which occurs exactly once. Hence the answer is -1.

见题面

见题面