using System;

public class Program

{

    public static void Main()

    {

        Console.Write("Enter you birthday: DD.MM.YYYY: ");

        string birthDay = Console.ReadLine();

​

        string[] userYear = birthDay.Split('.');

        int userYearInt = int.Parse(userYear[2]);

​

        int currentYear = DateTime.Now.Year;

​

         int userAge = currentYear - userYearInt;

        Console.WriteLine("User age is: {0}", userAge);

}

}