title: validate string based on a format
body: <p>I have a string that must be on the following format:</p>
  
  <p>XXXX-XX-XXX-XXXX-XXXXXXXXXX-X</p>
  
  <p>where X is an integer. The number of integers don't matter. I just need to make sure that the string:</p>
  
  <ul>
  <li>starts and ends with an integer</li>
  <li>contains only integers separated by dashes</li>
  </ul>
  
  <p>what would be the easiest way to validate that?</p>