for _ in range(int(input())):
    N = int(input())
    A = list(map(int,input().split()))
    ANSWER = "Yes" if A[0] != A[-1] else "No"
    B = [i for i in range(N) if A[i] != A[0]]
    if len(B) > 3: ANSWER = "Yes"
    for i in range(len(B) - 1):
        if B[i] + 1 == B[i + 1]: ANSWER = "Yes"
    print(ANSWER)