using System;
using System.Text;
public class MainClass
{
static void Main() {
StringBuilder sb = new StringBuilder();
sb.Append("A ").Append("B ").Append("C... ");
string built1 = sb.ToString();
sb.Append("D");
string built2 = sb.ToString();
Console.WriteLine( built1 );
Console.WriteLine( built2 );
}
}
A B C...
A B C... D