function solve () {
  let buttons = [...document.querySelectorAll('.add-product')]
  buttons.forEach(b => b.addEventListener('click', add))

  document.querySelector('.checkout').addEventListener('click', checkout)
  let totalPrice = 0
  let list = {}

  let textArea = document.querySelector('textArea')

  function add () {
    let product = this.parentNode.parentNode
    let name = product.querySelector('.product-title').textContent
    let money = +product.querySelector('.product-line-price').textContent
    list[name] = name
    totalPrice += money
    textArea.value += `Added ${name} for ${money.toFixed(2)} to the cart.\n`
  }

  function checkout () {
    textArea.value += `You bought ${Object.values(list).join(
      ', '
    )} for ${totalPrice.toFixed(2)}.`

    buttons.forEach(b => b.removeEventListener('click', add))
    this.removeEventListener('click', checkout)
  }
}