Ununion lists_Lists

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Threading.Tasks;

namespace Ununion_lists
{
    class Program
    {
        static void Main(string[] args)
        {
            List<int> primal = Console.ReadLine().Split(' ').Select(int.Parse).ToList();
            int n = int.Parse(Console.ReadLine());
            int count = 0;
            while (count < n)
            {
                List<int> current = Console.ReadLine().Split(' ').Select(int.Parse).ToList();
                count++;
                foreach (int number in current)
                {
                    if (!primal.Contains(number))
                    {
                        primal.Add(number);
                    }
                    else
                    {
                        primal.RemoveAll(a => a == number);
                    }
                }
            }
            primal.Sort();
            Console.WriteLine(string.Join(" ", primal));
        }
    }
}