package com.company;
import java.util.*;
public class Main {

    public static void main(String[] args) {
        Scanner input = new Scanner(System.in);
        int num = Integer.parseInt(input.nextLine());
        int swap;
        int[] arr = new int[2 * num];
        int[] first_array = new int[num];
        int[] second_array = new int[num];
        String doubles_string;

        for (int i = 0; i < num; i++) {
            doubles_string = input.nextLine();
            String doubles[] = doubles_string.split(" ");
            int[] doubles_int = Arrays.stream(doubles).mapToInt(Integer::parseInt).toArray();
            first_array[i] = doubles_int[0];
            second_array[i] = doubles_int[1];

            //String[] arr = Arrays.stream(strings.split(" ")).toArray(String[]::new);
            //int[] numbers = Arrays.stream(input.nextLine().split(" ")).mapToInt(e -> Integer.parseInt(e)).toArray();
        }

        for (int i = 0; i < num; i++) {
            if (i % 2 == 0) {
                swap = second_array[i];
                second_array[i] = first_array[i];
                first_array[i] = swap;
            }
        }

        for (int i = 0; i < num; i++) {
            System.out.print(second_array[i] + " ");
        }

        System.out.println();

        for (int i = 0; i < num; i++) {
            System.out.print(first_array[i] + " ");
        }
    }
}