问在c# visual studio中统计“姓名”和“姓氏”在文本中出现的次数

EN

using System;
using System.IO;

namespace Harry
{
    class Program
    {
        static void Main(string[] args)
        {
            string input = Console.ReadLine();
            StreamReader stream = File.OpenText("Harry Potter and the Sorcerer.txt");
            string text = stream.ReadToEnd();

            string woord = "";
            int count = 0;

            foreach (var item in text)
            {
                if (Char.IsLetter(item))
                {
                    woord = woord + item;
                }
                else
                {
                    if(woord == input)
                    {
                        count++; 
                    }
                    woord = "";
                }
            }
            Console.Write(input + ": " + count + " occurrences");
        }
    }
}