title: How to sort column with specific data separated by /
body: <p>I am trying to sort column with data like this:</p>
  
  <p>input:</p>
  
  <pre><code>11/2
  11/3a
  11/2b
  3/1
  2/5
  2/8
  3/5
  </code></pre>
  
  <p>how should it be sorted:</p>
  
  <pre><code>2/5
  2/8
  3/1
  3/5
  11/2
  11/2b
  11/3b
  </code></pre>
  
  <p>the cell is always in format number1/number2[optional letter]</p>
  
  <p>and should be sorted by number 1, then by number2, then by letter. How can I do this?</p>