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

namespace ConsoleApplication15
{
    class Program
    {
        static void Main(string[] args)
        {
            using (StreamReader sr = new StreamReader("D:\\New.txt"))
            {
                string str = sr.ReadLine();
                string strResult = null;

                foreach (char a in str)
                {
                    if (char.IsDigit(a))
                        strResult += a;
                }
            }

            using (StreamWriter sw = new StreamWriter("D:\\New.txt"))
            {
                sw.WriteLine();
            }
        }
    }
}