T = int(input())
for i in range(T):
N = int(input())
vals = list(map(int, input().split()))
dp = [0] * N
dp[0] = max(vals[0], 0)
dp[1] = max(vals[0], vals[1])
for i in range(2, N):
dp[i] = max(dp[i-2]+vals[i], dp[i-1])
print(dp[-1])