#!/usr/bin/env ruby

normal = "abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ"
rot13  = "nopqrstuvwxyzabcdefghijklmNOPQRSTUVWXYZABCDEFGHIJKLM"

STDIN.each_char do |char|
  candidate = char.tr!(normal, rot13)
  if candidate
    print candidate
  else
    print char
  end
end