﻿<?xml version="1.0"?>
<!DOCTYPE root [ 
<!ELEMENT root (#PCDATA)>
  <!ENTITY ha0 "Ha!">
  <!ENTITY ha1  "&ha0;&ha0;" >
  <!ENTITY ha2  "&ha1;&ha1;" >
  ...
  <!ENTITY ha29 "&ha28;&ha28;" >
  <!ENTITY ha30 "&ha29;&ha29;" >
]>
<root>&ha30;</root>
