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

namespace ConsoleApplication33
{
    class Program
    {
        static void Main(string[] args)
        {
            StringTool objString = new StringTool();

            Console.WriteLine("Введите строку ");
            objString.processedString = Console.ReadLine();
            Console.WriteLine(objString.LettersClean(Console.ReadLine()));

        }
    }

    class StringTool
    {
        public string processedString;

        public string LettersClean(string somestring)
        {
            string resultString = null;
            foreach (char a in somestring)
                if (!char.IsLetter(a))
                    resultString += a;
            return resultString;
        }
    }
}