MIME_Type.cs

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

namespace ConsoleApp6
{
    class Program
    {
        static void Main(string[] args)
        {
            int N = int.Parse(Console.ReadLine()); // Number of elements which make up the association table.
            int Q = int.Parse(Console.ReadLine()); // Number Q of file names to be analyzed.
            Dictionary<string, string> mimes = new Dictionary<string, string>();

            for (int i = 0; i < N; i++)
            {
                string[] inputs = Console.ReadLine().Split(' ');
                string EXT = inputs[0].ToLower(); // file extension
                string MT = inputs[1]; // MIME type.
                mimes.Add(EXT, MT);
            }

            for (int i = 0; i < Q; i++)
            {
                string FNAME = Console.ReadLine(); // One file name per line.
                string ext = FNAME.Substring(FNAME.LastIndexOf('.') + 1).ToLower();

                if (FNAME.Contains(".") && mimes.ContainsKey(ext))
                    Console.WriteLine(mimes[ext]);
                else
                    Console.WriteLine("UNKNOWN");
            }
        }
    }
}