import bisect
from collections import Counter

def max_kadomatsu_groups(test_cases):
    results = []
    for case in test_cases:
        N, L = case
        if N < 3:
            results.append(0)
            continue
        freq = list(Counter(L).values())
        max_possible = N // 3
        low, high = 0, max_possible
        best = 0
        while low <= high:
            mid = (low + high) // 2
            total = sum(min(f, mid) for f in freq)
            if total >= 3 * mid:
                best = mid
                low = mid + 1
            else:
                high = mid - 1
        results.append(best)
    return results

# Read input and process
import sys
def main():
    input = sys.stdin.read().split()
    ptr = 0
    T = int(input[ptr])
    ptr += 1
    test_cases = []
    for _ in range(T):
        N = int(input[ptr])
        ptr += 1
        L = list(map(int, input[ptr:ptr + N]))
        ptr += N
        test_cases.append((N, L))
    results = max_kadomatsu_groups(test_cases)
    for res in results:
        print(res)

if __name__ == '__main__':
    main()