title: Regular expression to match character repeated three times
body: <p>I need to simplify the following regular expression to include all the letters of the alphabet:</p>
  
  <pre><code>(a{3})|(b{3})|(c{3})|(z{3})|(A{3})|(B{3})|(C{3})|(Z{3})
  </code></pre>
  
  <p>In practice I want to find all the sequences of same three chars, for example:</p>
  
  <pre><code>aaa
  bbb
  nnn
  VVV
  JJJ
  </code></pre>
  
  <p>and so on.</p>