SetsOfElements

namespace SetsOfElements
{
    using System;
    using System.Collections.Generic;
    using System.Linq;

    public class SetsOfElements
    {
        public static void Main()
        {
            int[] lengths = Console.ReadLine().
                Trim()
                .Split(new[] { ' ', '\t' }, StringSplitOptions.RemoveEmptyEntries)
                .Select(int.Parse)
                .ToArray();

            int firstSetLength = lengths[0];
            int secondSetLength = lengths[1];

            HashSet<int> firstHashSet = new HashSet<int>();
            HashSet<int> secondHashSet = new HashSet<int>();

            for (int i = 0; i < firstSetLength; i++)
            {
                int firstSetNumber = int.Parse(Console.ReadLine());
                firstHashSet.Add(firstSetNumber);
            }

            for (int i = 0; i < secondSetLength; i++)
            {
                int secondSetNumber = int.Parse(Console.ReadLine());
                secondHashSet.Add(secondSetNumber);
            }

            var intersected = firstHashSet.Intersect(secondHashSet);

            foreach (var item in intersected)
            {
                Console.Write(item + " ");
            }
        }
    }
}