import heapq
import collections

def solve(N, Ls):
    counts = collections.Counter(Ls)
    vals = [-c for c in counts.values()]
    heapq.heapify(vals)
    while N:
        c = -vals[0]
        if c <= N // 3:
            return N // 3
        newc = (N - c) // 2
        N -= c - newc
        heapq.heapreplace(vals, -newc)
    return 0

T = int(input())
for t in range(T):
    N = int(input())
    Ls = list(map(int, input().split()))
    print(solve(N, Ls))