 <p>Nothing is wrong with your program. Codecademy has a bug reading any input that has a quote in it...</p> <p>Try it out:</p> <pre><code>gets </code></pre> <p>Just enter <code>'</code> to see it crash...</p> <p>My advice is to get your own local environment to develop on ruby. There are many many resources out there to help you install a simple ruby environment on any OS.</p> <p>After that, download and install <strong>Sublime Text</strong> and start creating your ruby source file. Then you will see that <code>ruby &lt;your_file&gt;.rb</code> will work perfectly as you expect.</p>