HTML
<ul>
    <li id="1">
        one
        <ul>
            <li id="2">
                two
                <ul>
                  <li id="4">four</li>
                </ul>
            </li>
            <li id="3">three</li>
        </ul>
    <li id = "5">
        Five
        <ul>
            <li id="6">six</li>
        </ul>

Javascript
var numberList = document.querySelector("#numberList");
numberList.addEventListener('keyup', handler)

function handler(e){
      if(e.type === 'keyup'){
            getId(e)
        }
    }