import java.io.OutputStream;
import java.io.IOException;
import java.io.InputStream;
import java.io.PrintWriter;
import java.util.StringTokenizer;
import java.io.IOException;
import java.io.BufferedReader;
import java.io.InputStreamReader;
import java.io.InputStream;

/**
 * Built using CHelper plug-in
 * Actual solution is at the top
 */
public class Main {
    public static void main(String[] args) {
        InputStream inputStream = System.in;
        OutputStream outputStream = System.out;
        InputReader in = new InputReader(inputStream);
        PrintWriter out = new PrintWriter(outputStream);
        Tasko solver = new Tasko();
        solver.solve(1, in, out);
        out.close();
    }

    static class Tasko {
        public void solve(int testNumber, InputReader in, PrintWriter out) {
            int t = in.nextInt();
            for (int i = 0; i < t; i++) {
                int n = in.nextInt();
                int[] sequence = new int[n];
                int max = Integer.MIN_VALUE;
                for (int j = 0; j < n; j++) {
                    sequence[j] = in.nextInt();
                    if(sequence[j] > max)
                        max = sequence[j];
                }
                if(max < 0){
                    out.println(max);
                    continue;
                }
                long sum = 0;
                boolean positive = true;
                int current = 0;
                for (int j = 0; j < sequence.length; j++) {
                    int value = sequence[j];
                    if(positive){
                        if(value >= current)
                            current = value;
                        if(j == sequence.length-1 || sequence[j+1] < 0){
                            sum += current;
                            positive = false;
                            current = Integer.MIN_VALUE;
                        }
                    } else {
                        if(value >= current)
                            current = value;
                        if(j == sequence.length-1 || sequence[j+1] > 0){
                            sum += current;
                            positive = true;
                        }
                    }
                }
                out.println(sum);
            }
        }

    }

    static class InputReader {
        public BufferedReader reader;
        public StringTokenizer tokenizer;

        public InputReader(InputStream stream) {
            reader = new BufferedReader(new InputStreamReader(stream), 32768);
            tokenizer = null;
        }

        public String next() {
            while (tokenizer == null || !tokenizer.hasMoreTokens()) {
                try {
                    tokenizer = new StringTokenizer(reader.readLine());
                } catch (IOException e) {
                    throw new RuntimeException(e);
                }
            }
            return tokenizer.nextToken();
        }

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

    }
}
 