#!/usr/bin/ruby

def gcd(a, b)

  if a > b

    a, b = [b, a]

  end

  if a == b or a == 1

    return a

  end

  return gcd(a, b-a)

end

a, b = ARGV[0..1].map{|arg| arg.to_i}

puts "The gcd of %i and %i is %i\n" % [a, b, gcd(a,b)]