import os
import sys
from collections import Counter
from io import BytesIO, IOBase

BUFSIZE = 8192


class FastIO(IOBase):
    newlines = 0

    def __init__(self, file):
        self._fd = file.fileno()
        self.buffer = BytesIO()
        self.writable = "x" in file.mode or "r" not in file.mode
        self.write = self.buffer.write if self.writable else None

    def read(self):
        while True:
            b = os.read(self._fd, max(os.fstat(self._fd).st_size, BUFSIZE))
            if not b:
                break
            ptr = self.buffer.tell()
            self.buffer.seek(0, 2), self.buffer.write(b), self.buffer.seek(ptr)
        self.newlines = 0
        return self.buffer.read()

    def readline(self):
        while self.newlines == 0:
            b = os.read(self._fd, max(os.fstat(self._fd).st_size, BUFSIZE))
            self.newlines = b.count(b"\n") + (not b)
            ptr = self.buffer.tell()
            self.buffer.seek(0, 2), self.buffer.write(b), self.buffer.seek(ptr)
        self.newlines -= 1
        return self.buffer.readline()

    def flush(self):
        if self.writable:
            os.write(self._fd, self.buffer.getvalue())
            self.buffer.truncate(0), self.buffer.seek(0)


class IOWrapper(IOBase):
    def __init__(self, file):
        self.buffer = FastIO(file)
        self.flush = self.buffer.flush
        self.writable = self.buffer.writable
        self.write = lambda s: self.buffer.write(s.encode("ascii"))
        self.read = lambda: self.buffer.read().decode("ascii")
        self.readline = lambda: self.buffer.readline().decode("ascii")


sys.stdin, sys.stdout = IOWrapper(sys.stdin), IOWrapper(sys.stdout)
input = lambda: sys.stdin.readline().rstrip("\r\n")
def cons(i,lst):
    x=0
    for z in range(i,len(lst)):
        if lst[z]<0:
            break
        else:
            x+=1
    if x==len(lst)-i:
        try:
            return max(lst[i:z+1]), z+1
        except:
            return lst[z], z+1
    else:
        try:
            return max(lst[i:z]),z
        except:
            return lst[z],z
def negCons(i,lst):
    x = 0
    for z in range(i, len(lst)):
        if lst[z] > 0:
            break
        else:
            x += 1
    if x == len(lst) - i:
        try:
            return max(lst[i:z+1]), z+1
        except:
            return lst[z], z+1
    else:
        try:
            return max(lst[i:z]), z
        except:
            return lst[z], z
a=int(input())
for k in range(a):
    a=int(input())
    lst=list(map(int,input().split()))
    i,ans=0,0
    while i < a:
        if lst[i] > 0:
            temp, lol = cons(i, lst)
            ans += temp
        else:
            temp, lol = negCons(i, lst)
            ans += temp
        i = lol
    print(ans)

