import sys
import io, os
input = io.BytesIO(os.read(0,os.fstat(0).st_size)).readline

def solve(A):
    dp = [0]*(n+1)
    for i in range(2, n):
        dp[i+1] = max(dp[i], 0)
        if A[i-2] < A[i-1] > A[i] and A[i-2] != A[i]:
            dp[i+1] = max(dp[i+1], dp[i-2]+A[i-2])
        elif A[i-2] > A[i-1] < A[i] and A[i-2] != A[i]:
            dp[i+1] = max(dp[i+1], dp[i-2]+A[i-2])
    return dp[n]

t = int(input())
for _ in range(t):
    n = int(input())
    A = list(map(int, input().split()))
    ans = solve(A)
    ans = max(ans, solve(A[1:]+A[0:1]))
    ans = max(ans, solve(A[2:]+A[0:2]))
    print(ans)