using System;

public class Program

{

    public static void Main()

    {

        Console.WriteLine(ExtractVersion("12.34"));

    }

     public static string ExtractVersion(string version)

     {

         var len = 0;

​

         for (int i = 0; i < 3; i++)

             len = version.IndexOf('.', len + 1);

​

         return len > 0 ?

             version.Substring(0, len) : version;

     }

}