using System;
using System.Linq;

namespace ArraysExercisesZigZagArrays
{
    class Program
    {
        static void Main(string[] args)
        {
            int num = int.Parse(Console.ReadLine());
            string[] arrayOne = new string[num];
            string[] arrayTwo = new string[num];

            for (int i = 1; i <= num; i++)
            {
                string[] currArr = Console.ReadLine().Split().ToArray();
                if (i % 2 == 1)
                {
                    arrayOne[i - 1] = currArr[0];
                    arrayTwo[i - 1] = currArr[1];
                } else
                {
                    arrayOne[i - 1] = currArr[1];
                    arrayTwo[i - 1] = currArr[0];
                }
            }
            Console.WriteLine(string.Join(" ", arrayOne));
            Console.WriteLine(string.Join(" ", arrayTwo));
        }
    }
}