function groupByFirstLetter(words: string[]): Record<string, string[]> {

  const output = {};
  

  words.forEach(word => {
    const letter = word.at(0).toLowerCase();
    const wordsByLetter = output[letter] || [];
    
    wordsByLetter.push(word)
    output[letter] = wordsByLetter;
  })


  return output;
}

// No modificar: necesario para evaluar el resultado.
export { groupByFirstLetter };