using System;
using System.Text;
class MainClass
{
public static void Main()
{
StringBuilder myStringBuilder = new StringBuilder();
myStringBuilder.Append("friends");
myStringBuilder.Insert(2, "friends, ");
myStringBuilder.Insert(2, "Romans, ", 3);
Console.WriteLine("myStringBuilder = " + myStringBuilder);
myStringBuilder.Replace(',', '?');
Console.WriteLine("myStringBuilder = " + myStringBuilder);
}
}