import sys

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

input = sys.stdin.readline

t = int(input())
for _ in range(t):
    n = int(input())
    a = list(map(int, input().split()))
    ans = 0
    for _ in range(3):
        dp = [0] * (n + 1)
        for i in range(n):
            if i + 2 < n and is_kadomatsu(a[i], a[i + 1], a[i + 2]) and dp[i + 3] < dp[i] + a[i]:
                dp[i + 3] = dp[i] + a[i]
            if dp[i + 1] < dp[i]:
                dp[i + 1] = dp[i]
        ans = max(ans, dp[n])
        a = a[1:] + [a[0]]
    print(ans)