using System;
using System.IO;

namespace Files
{
    class Program
    {
        static void Main(string[] args)
        {
            string nameFile = "Test.txt";
            if (!File.Exists(nameFile))
            {
                File.Create(nameFile);
            }

            //File.WriteAllText(nameFile, "Write");
            File.AppendAllText(nameFile, "BomBom");
            Console.WriteLine(File.ReadAllText(nameFile));

            Console.ReadLine();
        }
    }
}