# -*- coding: utf-8 -*-
def calc(Alist, M):
    Alist.sort()
    Alist.append(0)
    max1 = 0
    max2 = 0
    cnt = 1
    ccc = 1
    for i in range(1, M+1):
        if Alist[i] == Alist[i-1]:
            cnt += 1
        elif Alist[i] != Alist[i-1]:
            ccc += 1
            if max1 <= cnt:
                max2 = max1
                max1 = cnt
            if max2 < cnt < max1:
                max2 = cnt
            cnt = 1
    m3 = M // 3
    if max1 <= m3:
        ans = m3
    else:
        N = M - max1
        n2 = N // 2
        if max2 <= n2:
            ans = n2
        elif n2 < max2:
            ans = M - max1 - max2
    if ccc <= 3:
        ans = 0
    return ans


Alist = []
out = []
L = input()
for i in range(0, L):
    M = input()
    Alist = map(int, raw_input().split())
    out.append(calc(Alist, M))
for i in range(0, L):
    print out[i]