require 'rexml/document'

BAD_ELEMENTS=['param','script','applet', 'style'] # Eliminate with contents
GOOD_ATTRIBUTES=['title','cite','alt','rel','rev'] # Leave alone

def handle_element(element)
  if BAD_ELEMENTS.member? element.name
    element.remove
  else
    element.attributes.each_attribute do |attr|
      attr.remove unless GOOD_ATTRIBUTES.member? attr.name
    end
    element.elements.each {|subel| handle_element subel}
  end
end

doc=REXML::Document.new($stdin)

handle_element(doc.root)

doc.write