import java.util.*;
import java.io.DataInputStream; 
import java.io.FileInputStream; 
import java.io.IOException; 
import java.io.InputStreamReader; 
import java.util.Scanner; 
import java.util.StringTokenizer; 
 public class Ja{

static class Reader 
    { 
        final private int BUFFER_SIZE = 1 << 16; 
        private DataInputStream din; 
        private byte[] buffer; 
        private int bufferPointer, bytesRead; 
  
        public Reader() 
        { 
            din = new DataInputStream(System.in); 
            buffer = new byte[BUFFER_SIZE]; 
            bufferPointer = bytesRead = 0; 
        } 
  
        public Reader(String file_name) throws IOException 
        { 
            din = new DataInputStream(new FileInputStream(file_name)); 
            buffer = new byte[BUFFER_SIZE]; 
            bufferPointer = bytesRead = 0; 
        } 
  
        public String readLine() throws IOException 
        { 
            byte[] buf = new byte[64]; // line length 
            int cnt = 0, c; 
            while ((c = read()) != -1) 
            { 
                if (c == '\n') 
                    break; 
                buf[cnt++] = (byte) c; 
            } 
            return new String(buf, 0, cnt); 
        } 
  
        public int nextInt() throws IOException 
        { 
            int ret = 0; 
            byte c = read(); 
            while (c <= ' ') 
                c = read(); 
            boolean neg = (c == '-'); 
            if (neg) 
                c = read(); 
            do
            { 
                ret = ret * 10 + c - '0'; 
            }  while ((c = read()) >= '0' && c <= '9'); 
  
            if (neg) 
                return -ret; 
            return ret; 
        } 
  
        public long nextLong() throws IOException 
        { 
            long ret = 0; 
            byte c = read(); 
            while (c <= ' ') 
                c = read(); 
            boolean neg = (c == '-'); 
            if (neg) 
                c = read(); 
            do { 
                ret = ret * 10 + c - '0'; 
            } 
            while ((c = read()) >= '0' && c <= '9'); 
            if (neg) 
                return -ret; 
            return ret; 
        } 
  
        public double nextDouble() throws IOException 
        { 
            double ret = 0, div = 1; 
            byte c = read(); 
            while (c <= ' ') 
                c = read(); 
            boolean neg = (c == '-'); 
            if (neg) 
                c = read(); 
  
            do { 
                ret = ret * 10 + c - '0'; 
            } 
            while ((c = read()) >= '0' && c <= '9'); 
  
            if (c == '.') 
            { 
                while ((c = read()) >= '0' && c <= '9') 
                { 
                    ret += (c - '0') / (div *= 10); 
                } 
            } 
  
            if (neg) 
                return -ret; 
            return ret; 
        } 
  
        private void fillBuffer() throws IOException 
        { 
            bytesRead = din.read(buffer, bufferPointer = 0, BUFFER_SIZE); 
            if (bytesRead == -1) 
                buffer[0] = -1; 
        } 
  
        private byte read() throws IOException 
        { 
            if (bufferPointer == bytesRead) 
                fillBuffer(); 
            return buffer[bufferPointer++]; 
        } 
  
        public void close() throws IOException 
        { 
            if (din == null) 
                return; 
            din.close(); 
        } 
    } 
 	 public static void main(String args[] ) throws Exception {

 	 	Reader s=new Reader();
 	 	int t=s.nextInt();
 	 	while(t-->0){
 	 		int n=s.nextInt();
 	 		int a[]=new int[n];
 	 		int max1=Integer.MIN_VALUE;
 	 		for(int i=0;i<n;i++){
 	 		a[i]=s.nextInt();
 	 		if(a[i]>max1)
 	 		max1=a[i];
 	 		}
 	 		List<Integer>l=new ArrayList<Integer>();
 	 		
 	 		l.add(a[0]);
 	 		
 	 		for(int i=1;i<n;i++){
 	 		    if(l.get(l.size()-1)*a[i]<0)
 	 		    
 	 		    l.add(a[i]);
 	 		    else{
 	 		        int max=0,min=0;
 	 		        
 	 		        max=Math.max(l.get(l.size()-1),a[i]);
 	 		       l.remove(l.size()-1);
 	 		       l.add(max);
 	 		       
 	 		    }
 	 		}
 	 		//System.out.println("Size="+l.size());
 	 		if(l.size()==1)
 	 		System.out.println(max1);
 	 		else{
 	 		   // int b[]=new int[l.size()];
 	 		    long ss=0;
 	 		for(int i=0;i<l.size();i++)
 	 		{
 	 		    ss+=l.get(i);
 	 		   // b[i]=ss;
 	 		}
 	 		
 	 			System.out.println(ss);
 	 		
 	 	}
 	 	}
 	 }
 }