Как подсчитать элементы в списке в Vanilla Javascript?

// Cache your elements
const title = document.getElementById('title');
const list = document.getElementById('list');
const input = document.getElementById('todoInput');
const add = document.getElementById('add')

// A new updateCount function
function updateCount() {
  const count = list.childElementCount;

  // Using a template literal is tidier than string concatenation
  // https://developer.mozilla.org/en/docs/Web/JavaScript/Reference/Template_literals
  title.innerHTML = `You have ${count} to-dos.`;
}

function todoList() {
  const item = input.value
  const text = document.createTextNode(item)
  const newItem = document.createElement('li')
  const check = document.createElement('span')
  check.className = 'circle'
  newItem.appendChild(check)
  newItem.appendChild(text)
  list.appendChild(newItem)
  input.value = '';

  // Call your updateCount function after a new item
  // has been added
  updateCount();
}

// Call updateCount initially when the page loads
updateCount();
add.addEventListener('click', todoList, false);

<div class = "progress">
  <div id = "title"></div>
</div>

<ul id = "list">
  <li><span class = "circle"></span>Build a task app</li>
  <li><span class = "circle"></span>Do exercise</li>
  <li><span class = "circle"></span>Buy headphones</li>
</ul>

<input id = "todoInput" />
<button id = "add">Add</button>