<oerjan> # Stolen from Roger9//`learn Bureaucracy (from French bureau, "burrow") is a political system in which squirrels rule the nation, and burrow their nuts.

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