#!/usr/bin/env ruby


require "rexml/document"

input = STDIN.readlines.join

output = input 

begin
  seen_urls = Hash.new(false)

  rexml_tree = REXML::Document.new input

  links = rexml_tree.root.get_elements("//h3[@class='desc']/a[1]")

  links.each { | link |

    if !seen_urls[link.attribute("href").to_s] 
       seen_urls[link.attribute("href").to_s] = true
    else
       link.parent.parent.remove
    end
  }

  output = rexml_tree

ensure
  STDOUT.write(output)
end