import sys
from math import log2,floor
# import bisect
# from collections import deque

Ri = lambda : [int(x) for x in sys.stdin.readline().split()]
ri = lambda : sys.stdin.readline().strip()
 
def input(): return sys.stdin.readline().strip()
def list2d(a, b, c): return [[c] * b for i in range(a)]
def list3d(a, b, c, d): return [[[d] * c for j in range(b)] for i in range(a)]
def list4d(a, b, c, d, e): return [[[[e] * d for j in range(c)] for j in range(b)] for i in range(a)]
def ceil(x, y=1): return int(-(-x // y))
def INT(): return int(input())
def MAP(): return map(int, input().split())
def LIST(N=None): return list(MAP()) if N is None else [INT() for i in range(N)]
def Yes(): print('Yes')
def No(): print('No')
def YES(): print('YES')
def NO(): print('NO')
INF = 10 ** 18
MOD = 10**9+7

for _ in range(int(ri())):
    n = int(ri())
    a = Ri()
    minn = INF
    maxx = -INF
    ans = []
    minn = maxx = a[0]
    for i in range(1,len(a)):
        prevminn = minn
        prevmaxx = maxx
        minn = min(minn,a[i])
        maxx = max(maxx,a[i])
        if prevmaxx < 0 and maxx > 0:
            ans.append(prevmaxx)
            minn = maxx=  maxx
        if prevminn > 0 and minn < 0:
            ans.append(prevmaxx)
            minn = maxx = minn
    # if a[n-1] < 0:
    ans.append(maxx)
    print(sum(ans))


