title: Regex number and hyphen
body: <p>I'm trying to match number with regular expression like:</p>
  
  <pre><code>34-7878-3523-4233
  </code></pre>
  
  <p>with this:</p>
  
  <pre><code>^[0-9][0-9-]*-[0-9-]*[0-9]$
  </code></pre>
  
  <p>But the expression also allow</p>
  
  <p>34--34--------88</p>
  
  <p>So how can I allow only one hyphen between the number?</p>