import sys
import os
import time
import collections
from collections import Counter, deque
import itertools
import math
import timeit
import random
import string

#########################
# imgur.com/Pkt7iIf.png #
#########################

def sieve(n):
    if n < 2: return list()
    prime = [True for _ in range(n + 1)]
    p = 3
    while p * p <= n:
        if prime[p]:
            for i in range(p * 2, n + 1, p):
                prime[i] = False
        p += 2
    r = [2]
    for p in range(3, n + 1, 2):
        if prime[p]:
            r.append(p)
    return r

def divs(n, start=1):
    divisors = []
    for i in range(start, int(math.sqrt(n) + 1)):
        if n % i == 0:
            if n / i == i:
                divisors.append(i)
            else:
                divisors.extend([i, n // i])
    return divisors

def divn(n, primes):
    divs_number = 1
    for i in primes:
        if n == 1:
            return divs_number
        t = 1
        while n % i == 0:
            t += 1
            n //= i
        divs_number *= t

def flin(d, x, default=-1):
    left = right = -1
    for i in range(len(d)):
        if d[i] == x:
            if left == -1: left = i
            right = i
    if left == -1:
        return default, default
    else:
        return left, right

def ceil(n, k): return n // k + (n % k != 0)
def ii(): return int(input())
def mi(): return map(int, input().split())
def li(): return list(map(int, input().split()))
def lcm(a, b): return abs(a * b) // math.gcd(a, b)
def prr(a, sep=' '): print(sep.join(map(str, a)))
def dd(): return collections.defaultdict(int)
def ddl(): return collections.defaultdict(list)


# input = sys.stdin.readline

MAX = 10**9
for _ in range(ii()):
    n = ii()
    d = li()
    i = 0
    s = 0
    while i < n:
        j = i

        if d[j] < 0:
            t = -MAX
            while j < n and d[j] < 0:
                t = max(t, d[j])
                j += 1
        else:
            t = 0
            while j < n and d[j] > 0:
                t = max(t, d[j])
                j += 1
        s += t
        i = j
    print(s)









