Here is your task. Given a sequence A₁, A₂,.....A_N , you have to find the maximum possible difference between sum of all elements of subsequence S of length K such that S₁≥S₂≥..........S_K and sum of all elements of subsequence D of length same as S such that D₁≤D₂≤.........D_n (i.e (S₁+S₂+.....S_K) - (D₁+D₂+.......D_K)).
NOTE: Elements of both subsequences may be same or different.

INPUT

Input consists of number of test cases T.
Each test case contains size of array i.e N and K length of subsequences.
Next line contains N space separated elements of array.

OUTPUT

You have to print the maximum possible difference between two subsequences. If any of subsequences do not exist print "-1" without the quotes.

CONSTRAINTS

1 <= T <= 100
1 <= N <= 10^4
1 <= a[i] <= 10^5
1 <= k <=100