title: Regular expression that matches any string parenthesized n times
body: <p>For example, it should match <code>(aaa)</code>, <code>((aaa))</code>, <code>(((aaa)))</code>, but not <code>((aaa)</code> or <code>(aaa))</code>.<br />
  Is it even possible?</p>
  
  <p>P.S. If it matters, I need this regular expression for JavaScript.</p>