text: function solve() {
      document.querySelector('#exercise button').addEventListener('click', () => {
          let currentInput = document.querySelector("#exercise article input");
  
          if (currentInput.value !== '') {
              let inputValue = currentInput.value.toLowerCase();
  
              inputValue = inputValue.substring(0, 1).toUpperCase() + inputValue.substring(1);
  
              const childIndex = inputValue.charCodeAt(0) - 'A'.charCodeAt(0);
  
              let dbCurrentLi = document.querySelector(`#exercise div ol li:nth-child(${childIndex + 1})`);
  
              dbCurrentLi.textContent ? dbCurrentLi.textContent += ', ' + inputValue : dbCurrentLi.textContent = inputValue;
  
              currentInput.value = '';
          }
      });
  }