Class C# Tutorial

using System;
using System.Collections.Generic;
using System.Data;
using System.Linq;
using System.Text;
public class MainClass{
   public static void Main(string[] args){   
         String MyString = "a;@b,c:d?e+ hello!";
         int CharCount = MyString.SpecialCharCount();
         Console.WriteLine(CharCount.ToString());
   }
}
   public static class MyStrings
   {
      public static int SpecialCharCount(this String Str)
      {
         var CharQuery = from ThisCount in Str where ThisCount == '!' 
                         || ThisCount == '@'
                         || ThisCount == ';'
                         || ThisCount == ','
                         || ThisCount == ' '
                         select ThisCount;
         return CharQuery.Count();
      }
   }