using System;

using System.Linq;

public class Program

{

    public static void Main()

    {

        string str = "A man, a plan, a canal: Panama";

        Console.WriteLine(IsPalindrome(str));

    }

    static bool IsPalindrome(string str)

    {

        var newstr = new string(str.Where(p => IsPunctuation(p))

                                    .ToArray()).ToLower();

        Console.WriteLine(newstr);

        return newstr.Equals(new string(newstr.Reverse().ToArray()));           

    }

    static bool IsPunctuation(char p)

    { 

        return !char.IsPunctuation(p) && !char.IsWhiteSpace(p) && !char.Equals(p, '`');

    }

}