input: Write a python function to find all words of length n.
  assert find_words_of_length_n(["apple", "banana", "cherry", "date", "fig", "grape"], 5) == ["apple", "grape"]
  assert find_words_of_length_n(["python", "java", "c", "ruby", "swift"], 4) == ["java", "ruby"]
  assert find_words_of_length_n(["hello", "world", "hi", "bye"], 2) == ["hi"]
output: def find_words_of_length_n(words, n):
      return [word for word in words if len(word) == n]