write a go solution for Description:
There are 2n positive integers written on a whiteboard. Being bored, you decided to play a one-player game with the numbers on the whiteboard.

You start with a score of 0. You will increase your score by performing the following move exactly n times:

- Choose two integers x and y that are written on the whiteboard.
- Add min(x,y) to your score.
- Erase x and y from the whiteboard.

Note that after performing the move n times, there will be no more integers written on the whiteboard.

Find the maximum final score you can achieve if you optimally perform the n moves.

Input Format:
Each test contains multiple test cases. The first line contains a single integer t (1<=t<=5000) — the number of test cases. The description of the test cases follows.

The first line of each test case contains a single integer n (1<=n<=50) — the number of integers written on the whiteboard is 2n.

The second line of each test case contains 2n integers a_1,a_2,ldots,a_2n (1<=a_i<=10^7) — the numbers written on the whiteboard.

Output Format:
For each test case, output the maximum final score that you can achieve.

Note:
In the first test case, you can only make one move. You select x=2 and y=3, and your score will be min(x,y)=2.

In the second test case, the following is a sequence of moves that achieves a final score of 2:

- In the first move, select x=1 and y=1. Then, add min(x,y)=1 to the score. After erasing x and y, the integers left on the whiteboard are 1 and 2.
- In the second move, select x=1 and y=2. Then, add min(x,y)=1 to the score. After removing x and y, no more integers will be left on the whiteboard.

In the third test case, you will perform the move thrice, adding 1 to the score each time.. Output only the code with no comments, explanation, or additional text.