Kinich wakes up to the start of a new day. He turns on his phone, checks his mailbox, and finds a mysterious present. He decides to unbox the present.

Kinich unboxes an array $$$a$$$ with $$$n$$$ integers. Initially, Kinich's score is $$$0$$$. He will perform the following operation any number of times:

- Select two indices $$$i$$$ and $$$j$$$ $$$(1 \leq i < j \leq n)$$$ such that neither $$$i$$$ nor $$$j$$$ has been chosen in any previous operation and $$$a_i = a_j$$$. Then, add $$$1$$$ to his score.

Output the maximum score Kinich can achieve after performing the aforementioned operation any number of times.

Input format:
The first line contains an integer $$$t$$$ ($$$1 \leq t \leq 500$$$) — the number of test cases.

The first line of each test case contains an integer $$$n$$$ ($$$1 \leq n \leq 20$$$) — the length of $$$a$$$.

The following line of each test case contains $$$n$$$ space-separated integers $$$a_1, a_2, \ldots, a_n$$$ ($$$1 \leq a_i \leq n$$$).
Output format:
For each test case, output the maximum score achievable on a new line.
Example Input 0:
5
1
1
2
2 2
2
1 2
4
1 2 3 1
6
1 2 3 1 2 3

Example Output 0:
0
1
0
1
3

Notes:
In the first and third testcases, Kinich cannot perform any operations.

In the second testcase, Kinich can perform one operation with $$$i=1$$$ and $$$j=2$$$.

In the fourth testcase, Kinich can perform one operation with $$$i=1$$$ and $$$j=4$$$.

Example input:
5
1
1
2
2 2
2
1 2
4
1 2 3 1
6
1 2 3 1 2 3


Example output:
0
1
0
1
3