def kado(a, b, c):
    if len(set((a, b, c))) != 3:
        return False
    return b in [max(a, b, c), min(a, b, c)]

def solve():
    n = int(input())
    A = list(map(int, input().split()))
    ans = 0
    for _ in range(3):
        dp = [0] * (n + 1)
        for i in range(3, n + 1):
            a, b, c = A[i - 3:i]
            dp[i] = dp[i - 1]
            if kado(a, b, c):
                dp[i] = max(dp[i], dp[i - 3] + a)
        ans = max(ans, dp[-1])
        A = A[1:] + A[:1]
    print(ans)
    
for _ in range(int(input())):
    solve()