Implement CLI application by editing main.rb.
You may add new files to keep your code clean, if it is allowed in your challenge.

In main.rb, there is a function called main, which gives command line arguments as argv.

def main(argv)
  # code to run
end

argv passed here is came from index.rb which passes ARGV to main function.

Use the standard puts method to output results to stdout.

puts "Hello World"

If you want to use external libraries, do the following:

• Write the library name in Gemfile