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