using System;
using System.Collections.Generic;
using System.Linq;

class Program
{
    static void Main()
    {
        try
        {
            // Read size of first array
            Console.Write("Enter size of first array (n): ");
            if (!int.TryParse(Console.ReadLine(), out int n) || n < 0)
            {
                Console.WriteLine("Invalid input. Please enter a non-negative integer.");
                return;
            }

            // Read size of second array
            Console.Write("Enter size of second array (m): ");
            if (!int.TryParse(Console.ReadLine(), out int m) || m < 0)
            {
                Console.WriteLine("Invalid input. Please enter a non-negative integer.");
                return;
            }

            // Read first array
            Console.WriteLine($"Enter {n} elements for the first array (space-separated):");
            int[] arr1 = ReadArray(n);

            // Read second array
            Console.WriteLine($"Enter {m} elements for the second array (space-separated):");
            int[] arr2 = ReadArray(m);

            // Compute union, remove duplicates, and sort
            List<int> unionResult = arr1.Concat(arr2).Distinct().OrderBy(x => x).ToList();

            // Print result
            Console.WriteLine("Union of the arrays (sorted): " + string.Join(" ", unionResult));
        }
        catch (Exception ex)
        {
            Console.WriteLine($"An error occurred: {ex.Message}");
        }
    }

    static int[] ReadArray(int size)
    {
        while (true)
        {
            string[] input = Console.ReadLine()?.Split();
            if (input != null && input.Length == size && input.All(x => int.TryParse(x, out _)))
            {
                return input.Select(int.Parse).ToArray();
            }
            Console.WriteLine($"Invalid input. Please enter exactly {size} space-separated integers:"