input: 
  from Crypto.Cipher import AES
  
  def chpher(plaintext):
      """Encrypt the given plaintext using the AES algorithm.
      >>> cipher('Hello, World!')
      b'6s\xf9T\xd7\xd2\xeda{\xf8\xa9\xf7\r\xa2\x98\xd2'
      """
      key = b'Sixteen byte key'
      cipher = AES.new(key, AES.MODE_ECB)
      return cipher.encrypt(plaintext)
output:     padded_plaintext = plaintext + (AES.block_size - len(plaintext) % AES.block_size) * chr(AES.block_size - len(plaintext) % AES.block_size)
      return cipher.encrypt(padded_plaintext.encode())