How can I assign a width based on the number of elements contained in the parent?

Question

css

Here in ul 2 there is an extra, how to make the width of li 50%. And if there is a surplus of 4, then 25%?

<ul class="slick-dots" style="" role="tablist">
  <li class="" role="presentation">
   <button type="button" role="tab" id="slick-slide-control00" aria-controls="slick-slide00" aria-label="1 of 2" 
   tabindex="-1">1</button>
</li>
 <li role="presentation" class="slick-active">
   <button type="button" role="tab" id="slick-slide-control01" aria-controls="slick-slide04" aria-label="2 of 2" tabindex="-1">2</button>
 </li>
</ul>

Answer 1

https://jsfiddle.net/h1cj04yL/