using System;
public class Program
{
public static void Main()
string s = "123456789.001";
Console.WriteLine("new value:" + ExtractLong(s));
}
public static long ExtractLong(string s)
if(string.IsNullOrEmpty(s))
return 0;
/*
if(s.Contains("."))
int index = s.IndexOf('.');
s = s.Substring(0, index);
*/
return long.Parse(s);