using System.Text;

using System;

public class Program

{

​

  public static void Main()

  {

      StringBuilder sb = new StringBuilder

          ();

     sb.AppendLine("Test");

     sb.AppendLine("AppendLine");

     sb.Append("D");

     sb.Append("O");

     sb.Append("N");

     sb.Replace("DON","Kihot");

     Console.WriteLine(sb.ToString());

      Console.WriteLine(sb.ToString ()); 

      Console.WriteLine();

​

​

  }

  }

​

​