from collections import defaultdict

def solve():
    n = int(input())
    l = list(map(int, input().split()))
    d = defaultdict(int)
    for x in l:
        d[x] += 1
    v = list(d.values())
    v.sort(reverse=True)
    print(min(n // 3, sum(v[1:]) // 2, sum(v[2:])))

t = int(input())
for i in range(t):
    solve()