import sys
input=lambda:sys.stdin.readline().rstrip()
def kadomatsu(a):
	return (a[1]>a[0] and a[1]>a[2] and a[0]!=a[2]) or (a[1]<a[0] and a[1]<a[2] and a[0]!=a[2])
def solve():
	N=int(input())
	A=list(map(int,input().split()))
	ans=0
	for i in range(3):
		dp=[0 for i in range(N)]
		for j in range(2,N):
			dp[j]=dp[j-1]
			if kadomatsu(A[j-2:j+1]):
				dp[j]=max(dp[j],dp[j-3]+A[j-2])
		ans=max(ans,dp[N-1])
		A=A[1:]+[A[0]]
	print(ans)
T=int(input())
for i in range(T):
	solve()