t=int(input())
while t>0:
    t-=1
    n=int(input())
    A=list(map(int,input().split(' ')))
    sumA=0
    if A[0]>0:
        current="pos"
    else:
        current="neg"
    c=0
    for i in range(1,n):
        if current=="pos":
            if A[i]>0:
                pass
            else:
                sumA+=max(A[c:i])
                c=i
                current="neg"
        else:
            if A[i]<0:
                pass
            else:
                sumA+=max(A[c:i])
                c=i
                current="pos"
        if current=="neg" and A[i]<0 and i==n-1:
            sumA+=max(A[c:])
        elif current=="pos" and A[i]>0 and i==n-1:
            sumA+=max(A[c:])
    print(sumA)


