<b_jonas> slashlearn ance//Spelling of -ance/-ence words: advance, science, conference, experience, finance, insurance, licence, performance, reference, assistance, balance, defence, difference, distance, evidence, acceptance, appliance, audience, compliance, importance, influence, instance, intelligence, maintenance, preference, presence, sentence, sequence, substance, violence, absence, accordance, alliance, appearance, assurance, attendance, circumstance, clea

#!/usr/bin/python
s=set()
try:
 while True:
  l=raw_input()
  if l not in s:
   s.add(l)
   print(l)
except EOFError:
 pass