import sequtils,strutils,algorithm
var
    T = stdin.readline.parseInt
for t in 1..T:
    var
        N = stdin.readline.parseInt
        L = stdin.readline.split.map(parseInt)
        A : array[2, int]
        cnt : int
        a,b : int
    L.sort(system.cmp)
    for l in L:
        if A[0] == 0 or l == a:
            A[0] += 1
            a = l
        elif A[1] == 0 or l == b:
            A[1] += 1
            b = l
        else:
            A[0] -= 1
            A[1] -= 1
            cnt += 1
            if A[0] == 0:
                A[0] = A[1]
                a = b
                A[1] = 0

    echo cnt