input: Write a python function to remove words containing the letter 'a' from a sentence.
  assert remove_words_with_a("I am a strong girl") == "I strong girl"
  assert remove_words_with_a("This is a test of the function") == "This is test of the"
  assert remove_words_with_a("Amazing animals are awesome") == "awesome"
output: def remove_words_with_a(sentence):
      return ' '.join(word for word in sentence.split() if 'a' not in word.lower())