// package com.company;
import java.util.*;
import java.lang.*;
import java.io.*;
//****Use Integer Wrapper Class for Arrays.sort()****
public class CN3 {
    static PrintWriter out=new PrintWriter(new OutputStreamWriter(System.out));
    public static void main(String[] Args){
        FastReader scan=new FastReader();
        int t=scan.nextInt();
        while(t-->0){
            int n=scan.nextInt();
            long[] arr=new long[n];
            arr[0]=scan.nextInt();
            long sum=0;
            long max=arr[0];
            for(int i=1;i<n;i++){
                arr[i]=scan.nextInt();
                if(max*arr[i]<0){
                    sum+=max;
                    max=arr[i];
                }else{
                    max=Math.max(max,arr[i]);
                }
            }
            sum+=max;
            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;
        }
    }

}
