title: Match all characters except for those that start with specific characters
body: <p>I'm trying to figure out how to match all characters except for character array that starts with <code>_ah</code>:</p>
  
  <pre><code>_ah\foo
  _ah\foo\bar
  </code></pre>
  
  <p>This is my current regex: <code>\b(?!\_ah(\w+))\w+\b</code></p>
  
  <p>However this regex still matches the one listed above. What could be the problem in my regex?</p>