/* package whatever; // don't place package name! */

import java.util.*;
import java.lang.*;
import java.io.*;
import java.util.regex.*;
/* Name of the class has to be "Main" only if the class is public. */
class Ideone
{
	public static void main (String[] args) throws java.lang.Exception
	{
	    String str = "\bHellow\b world!!!\b\b\b.";
	    System.out.println(str.replaceAll("^\b+|(?:([^\b])(?=\\1*+(\\2?+\b)))+\\2", "").replace("\b","<B>"));
	}
}