import java.util.*;
import java.io.*;
import java.lang.*;

public class Main {
    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 IOException {
        Reader scn = new Reader();
        int t = scn.nextInt();
        StringBuilder res = new StringBuilder();

        while (t-- > 0) {
            int n = scn.nextInt();
            int[] arr = new int[n];

            for(int i = 0 ; i < n ; i++){
                arr[i] = scn.nextInt();
            }

            int i = 0;
            ArrayList<Integer> List = new ArrayList<>();
            long sum = 0;

            while(i < n){
                if(arr[i] < 0){
                    while( i < n && arr[i] < 0 ){
                        List.add(arr[i]);
                        i++;
                    }
                }else{
                    while( i < n && arr[i] > 0 ){
                        List.add(arr[i]);
                        i++;
                    }
                }

                int max = Integer.MIN_VALUE;
                int j = 0 ;

                while(j < List.size()){
                    max = Math.max(max, List.get(j));
                    j++;
                }
                sum += max;
                List.clear();
            }
            res.append(sum);
            res.append('\n');
        }
        System.out.println(res);
    }
}