Adjacent tag insertion in JavaScript

insertAdjacentHTML

Задание 1

Given an element:

html<div id="elem" style="border: 1px solid red;">
  <p>text</p>
  <p>text</p>
  <p>text</p>
</div>

Given an element. Insert the following tag before it:

html<div class="www"><p>text</p><p>text</p><input></div>