while loop with if condition in php

Can anyone please help to solve this issue using while loop and if condition . It's may be simple but i can't solve this.

  <div class="a">            <div class="a">           <div class="a"> 
 <div class="s">1</div>    <div class="s">2</div>     <div class="s">3</div>
 <div class="s">4</div>    <div class="s">5</div>     <div class="s">6</div>
 <div class="s">7</div>    <div class="s">8</div>     <div class="s">9</div>
     </div>                      </div>                     </div>

ie if only 3 elements present then

 <div class="a">            <div class="a">           <div class="a"> 
 <div class="s">1</div>    <div class="s">2</div>     <div class="s">3</div>
   </div>                      </div>                     </div>

etc.. Pls help to solve this problem.