Untitled

import java.util.*;

public class Main {
    public static void main(String[] args) {
        Scanner scanner = new Scanner(System.in);
        int n = scanner.nextInt();
        scanner.nextLine();
        Set<Node> numbers = new TreeSet<>(Comparator.comparing(Node::getAbs));
        for (int i = 0; i < n; i++) {
            numbers.add(new Node(i, scanner.nextInt()));
        }
        System.out.println(numbers);
    }

    public static class Node{
        private final int index;
        private int value;

        public Node(int index) {
            this.index = index;
        }

        public Node(int index, int value) {
            this.index = index;
            this.value = value;
        }

        public int getIndex() {
            return index;
        }

        public int getValue() {
            return value;
        }

        public int getAbs() {
            return Math.abs(value);
        }

        public void setValue(int value) {
            this.value = value;
        }

        @Override
        public String toString() {
            return "Node{" +
                    "index=" + index +
                    ", value=" + value +
                    '}';
        }
    }
}