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)
        {
            string str;
            string strResult = null;

            using (StreamReader sr = new StreamReader("D:\\New.txt"))
                str = sr.ReadToEnd();

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

            using (StreamWriter sw = new StreamWriter("D:\\New.txt"))
                foreach (char a in strResult)
                    sw.WriteLine(a + "\n");
        }
    }
}