t = int(input())
ans = []
for s in range(t):
    n = int(input())
    arr = [int(x) for x in input().split()]
    if n == 1:
        ans.append(arr[0])
    else:
        sump = 0
        start = arr[0]
        k = 0
        i = 1
        while i < n:
            if arr[i] * arr[k] < 0:
                sump += max(arr[k:i])
                k = i
            elif i == n - 1:
                sump += max(arr[k:])
            if k == n - 1:
                sump += arr[k]
            i += 1
        ans.append(sump)
for it in ans:
    print(it)
