input: Write a function to filter words longer than 3 characters.
  assert filter_long_words(['Cat', 'Dog', 'Bird', 'Fish', 'Turtle']) == ['Bird', 'Fish', 'Turtle']
  assert filter_long_words(['a', 'ab', 'abc', 'abcd', 'abcde']) == ['abcd', 'abcde']
  assert filter_long_words(['hello', 'hi', 'hey', 'hola']) == ['hello', 'hola']
output: def filter_long_words(words):
      return [word for word in words if len(word) > 3]