n = int(input())
while n:
m = int(input())
lt = list(map(int, input().split()))
f = [[0,0] for _ in range(m)]
f[0][0] = 0
f[0][1] = lt[0]
for i in range(1,m):
f[i][0] = max(f[i-1][0], f[i-1][1])
f[i][1] = f[i-1][0] + lt[i]
print(max(f[m-1][0],f[m-1][1]))
n -=1