import java.io.BufferedReader;
import java.io.IOException;
import java.io.InputStreamReader;
import java.util.Scanner;
import java.util.StringTokenizer;
import java.util.Arrays;

public class Main
{

     public static void main(String[] args)
    {
        FastReader s=new FastReader();
        int t = s.nextInt();

        while(t-->0)
        {
            int n = s.nextInt();
            int x= s.nextInt();
            int sum=0;
            int y=0;
            int arr[]= new int [n];
            for(int i=1;i<n;i++)
            {
                y=s.nextInt();
                if((x>0 && y>0) || (x<0 && y<0))
                {
                    x=Math.max(x,y);
                }
                else{
                    sum+=x;
                    x=y;
                }
            }
            sum=sum+x;
        System.out.println(sum);
        }

    }


    static class FastReader
    {
        BufferedReader br;
        StringTokenizer st;

        public FastReader()
        {
            br = new BufferedReader(new
                     InputStreamReader(System.in));
        }

        String next()
        {
            while (st == null || !st.hasMoreElements())
            {
                try
                {
                    st = new StringTokenizer(br.readLine());
                }
                catch (IOException  e)
                {
                    e.printStackTrace();
                }
            }
            return st.nextToken();
        }

        int nextInt()
        {
            return Integer.parseInt(next());
        }

        long nextLong()
        {
            return Long.parseLong(next());
        }

        double nextDouble()
        {
            return Double.parseDouble(next());
        }

        String nextLine()
        {
            String str = "";
            try
            {
                str = br.readLine();
            }
            catch (IOException e)
            {
                e.printStackTrace();
            }
            return str;
        }
    }


}
