#!/usr/bin/env ruby

def Atbash(m)
		ab = ('A'..'Z').to_a
		sust = {}
		ab.each_index{|i| sust[ab[i]] = ab[ab.size-i-1]}		
		m = m.upcase.gsub(/\W/,'')
		ma = m.split(//)
		nm = ''
		ma.each{|e|
				nm << sust[e]
		}
		nm
end
		
Kernel::exit(1) if ARGV[0].nil?
m = ARGV[0]
puts "M: #{Atbash(m)}"