t = int(input())
for _ in range(t):
    n = int(input())
    A = list(map(int, input().split()))
    A += A
    ans = 0
    for f in range(3):
        DP = [0 for _ in range(n + 1)]
        for i in range(3, n + 1):
            if len(set(A[f + i - 3:f + i])) < 3:
                DP[i] = DP[i - 1]
            else:
                if A[f + i - 3] < A[f + i - 2] > A[f + i - 1] or A[f + i - 3] > A[f + i - 2] < A[f + i - 1]:
                    DP[i] = max(DP[i - 1], DP[i - 3] + A[f + i - 3])
                else:
                    DP[i] = DP[i - 1]
        ans = max(ans, DP[n])
    print(ans)