import sys

def kado(a,b,c):
    if a==b or b==c or a==c:
        return False
    return min(a,b,c)==b or max(a,b,c)==b

input = sys.stdin.readline

for _ in range(int(input())):
    N = int(input())
    A = list(map(int,input().split()))

    res = 0

    dp = [0 for i in range(N)]
    dp[2] = kado(A[0],A[1],A[2]) * A[0]
    for i in range(3,N):
        dp[i] = max(dp[i-1],kado(A[i-2],A[i-1],A[i])*A[i-1]+dp[i-3])
    res = max(res,dp[-1])

    A = [A[i+1] for i in range(N-1)] + [A[0]]
    dp = [0 for i in range(N)]
    dp[2] = kado(A[0],A[1],A[2]) * A[0]
    for i in range(3,N):
        dp[i] = max(dp[i-1],kado(A[i-2],A[i-1],A[i])*A[i-1]+dp[i-3])
    res = max(res,dp[-1])

    A = [A[i+1] for i in range(N-1)] + [A[0]]
    dp = [0 for i in range(N)]
    dp[2] = kado(A[0],A[1],A[2]) * A[0]
    for i in range(3,N):
        dp[i] = max(dp[i-1],kado(A[i-2],A[i-1],A[i])*A[i-1]+dp[i-3])
    res = max(res,dp[-1])

    print(res)