5623：KK's Number

Our lovely KK has a funny mathematical game:This game requires two people,There are $N\left(1\leq N\leq 5*{10}^{4} \right)$ numbers,every time KK will take the numbers,first.Every time you can take any number of the numbers.Until the $N$ number is taken.The minimum number of numbers is the score for each time.KK and the opponent's strategy is as much as possible to make their score minus the opponent's score more.In this case,How much is the final KK score minus the opponent's score?

The first line of the input file contains an integer $T\left( 1\leq T\leq 10\right)$, which indicates the number of test cases.
For each test case, there are two lines,in the first line is a integer $N\left(1\leq N\leq 5*{10}^{4} \right)$,the other line has $N$ positive integers(no more than ${10}^{9}$).

For each test case, there are one lines,includes a integer,indicating the final KK's score minus the opponent's score.