title: Regex NOT or exclude match
body: <p>How do I make regex match and exclude certain character. 
  For example, I am making an regex for all country's TDL match. </p>
  
  <pre><code>[a-z]{1,}((?!.ru)|.kr|.lt|.cn|.uk|.id|)
  </code></pre>
  
  <p>or  </p>
  
  <pre><code>[a-z]{1,}.([a-z]{1,})
  </code></pre>
  
  <p>gsdfg.ru &lt;- This shall match</p>
  
  <p>sgkjsr.us &lt;- only .us should not match or should excluded</p>