T = int(input())
def iskadomatu(ll):
    if ll[0] == ll[1] or ll[1] == ll[2] or ll[2] == ll[0]:
        return False
    if (ll[0] > ll[1] and ll[1] < ll[2]) or (ll[0] < ll[1] and ll[1] > ll[2]):
        return True
    return False

lsans = []
for i in range(T):
    N = int(input())
    lsA = list(map(int,input().split()))
    ans = 0
    for j in range(3):
        dp = [0]*(N)
        for k in range(2,N):
            if iskadomatu(lsA[k-2:k+1]):
                dp[k] = max(dp[k-1],dp[k-3]+lsA[k-2])
            else:
                dp[k] = dp[k-1]
        ans = max(ans,max(dp))
        lsA = [lsA[-1]] + lsA[:-1]
    lsans.append(ans)
print(*lsans,sep='\n')