input: 
  class matching_criteria:
      """Creates a class named Song with two instance variables, title and artist, and three methods, str(), eq(), and length().
      >>> song1 = Song("Bohemian Rhapsody", "Queen")
      >>> print(song1)
      Title: Bohemian Rhapsody
      Artist: Queen
      >>> song2 = Song("Bohemian Rhapsody", "Queen")
      >>> song1 == song2
      True
      >>> song2.length()
      17
      """
      class Song:
          def __init__(self, title, artist):
              self.title = title
              self.artist = artist
    
          def __str__(self):
              return f'Title: {self.title}\nArtist: {self.artist}'
      
          def __eq__(self, other):
              return self.artist == other.artist and self.title == other.title
  
          def length(self):
              return len(self.title)
  
output:     
      class Song:
          def __init__(self, title, artist):
              self.title = title
              self.artist = artist
    
          def __str__(self):
              return f'Title: {self.title}\nArtist: {self.artist}'
      
          def __eq__(self, other):
              return self.artist == other.artist and self.title == other.title
  
          def length(self):
              return len(self.title)
  