text: function solve() {
      document.querySelector('#exercise button').addEventListener('click', () => {
          const name = document.querySelector('#exercise input');
          const list = document.querySelectorAll('ol li');
          const char = name.value
              .toUpperCase()[0];
          const index = char
              .charCodeAt() - 65;
          const formatedName = char + name.value.substr(1).toLowerCase();
          list[index].innerHTML 
              ? list[index].innerHTML += ', ' + formatedName
              : list[index].innerHTML = formatedName;
          name.value = '';
      });
  }
  