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

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

For each test case, output the maximum score achievable on a new line.

见题面 Input 部分

见题面 Output 部分

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 $j=4$.