import sys

input = sys.stdin.buffer.readline
t = int(input())


def check(a, b, c):
    if a == b or b == c or c == a:
        return False
    if b > c and b > a:
        return True
    if b < c and b < a:
        return True
    return False


def calc(A):
    dp = [[0] * (3) for _ in range(n - 1)]
    for i in range(n - 2):
        ni = i + 1
        a, b, c = A[i], A[i + 1], A[i + 2]
        for j in range(3):
            if check(a, b, c):
                nj = max(0, j - 1)
                dp[ni][nj] = max(dp[ni][nj], dp[i][j])
                if j == 0:
                    nj = 2
                    dp[ni][nj] = max(dp[ni][nj], dp[i][j] + a)
            else:
                nj = max(0, j - 1)
                dp[ni][nj] = max(dp[ni][nj], dp[i][j])
    return max(dp[-1])


for _ in range(t):
    n = int(input())
    A = list(map(int, input().split()))
    A2 = A[1:] + A[:1]
    A3 = A[2:] + A[:2]
    print(max(calc(A), calc(A2), calc(A3)))