title: Finding all 1 digit and 2 digits numbers in a larger number using regex
body: <p>I want to match all 1 digit and 2 digit numbers using regex.</p>
  <p>Subject string: <code>'12345'</code></p>
  <p>Expected match: <code>1,2,3,4,5,12,23,34,45</code></p>
  <p>I'm trying: <code>\d(\d)?</code> but as result i get <code>12,2,34,3,5</code></p>