title: django template to get number from alphanumeric
body: <p>In Django template, how can I get last 3 digits from a alphanumeric word, <strong><em>without</em></strong> using custom django filter.</p>
  
  <p>Eg: input will always be in this format: "Foo-bar123"</p>
  
  <p>output required: "123"</p>
  
  <p>I couldn't find any built-ins that could achieve this.</p>