text: #Executing - python3 MD5.py
  import math
   
  rotate_amounts = [7, 12, 17, 22, 7, 12, 17, 22, 7, 12, 17, 22, 7, 12, 17, 22,
                    5,  9, 14, 20, 5,  9, 14, 20, 5,  9, 14, 20, 5,  9, 14, 20,
                    4, 11, 16, 23, 4, 11, 16, 23, 4, 11, 16, 23, 4, 11, 16, 23,
                    6, 10, 15, 21, 6, 10, 15, 21, 6, 10, 15, 21, 6, 10, 15, 21]
   
  constants = [int(abs(math.sin(i+1)) * 2**32) & 0xFFFFFFFF for i in range(64)]
   
  init_values = [0x67452301, 0xefcdab89, 0x98badcfe, 0x10325476]
   
  functions = 16*[lambda b, c, d: (b & c) | (~b & d)] + \
              16*[lambda b, c, d: (d & b) | (~d & c)] + \
              16*[lambda b, c, d: b ^ c ^ d] + \
              16*[lambda b, c, d: c ^ (b | ~d)]
   
  index_functions = 16*[lambda i: i] + \
                    16*[lambda i: (5*i + 1)%16] + \
                    16*[lambda i: (3*i + 5)%16] + \
                    16*[lambda i: (7*i)%16]
   
  def left_rotate(x, amount):
      x &= 0xFFFFFFFF
      return ((x<<amount) | (x>>(32-amount))) & 0xFFFFFFFF
   
  def md5(message):
   
      message = bytearray(message) #copy our input into a mutable buffer
      orig_len_in_bits = (8 * len(message)) & 0xffffffffffffffff
      message.append(0x80)
      while len(message)%64 != 56:
          message.append(0)
      message += orig_len_in_bits.to_bytes(8, byteorder='little')
   
      hash_pieces = init_values[:]
   
      for chunk_ofst in range(0, len(message), 64):
          a, b, c, d = hash_pieces
          chunk = message[chunk_ofst:chunk_ofst+64]
          for i in range(64):
              f = functions[i](b, c, d)
              g = index_functions[i](i)
              to_rotate = a + f + constants[i] + int.from_bytes(chunk[4*g:4*g+4], byteorder='little')
              new_b = (b + left_rotate(to_rotate, rotate_amounts[i])) & 0xFFFFFFFF
              a, b, c, d = d, new_b, b, c
          for i, val in enumerate([a, b, c, d]):
              hash_pieces[i] += val
              hash_pieces[i] &= 0xFFFFFFFF
   
      return sum(x<<(32*i) for i, x in enumerate(hash_pieces))
   
  def md5_to_hex(digest):
      raw = digest.to_bytes(16, byteorder='little')
      return '{:032x}'.format(int.from_bytes(raw, byteorder='big'))
   
  if __name__=='__main__':
      demo = [b"", b"a", b"abc", b"message digest", b"abcdefghijklmnopqrstuvwxyz",
              b"ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789",
              b"12345678901234567890123456789012345678901234567890123456789012345678901234567890"]
      for message in demo:
          print(md5_to_hex(md5(message)),' <= "',message.decode('ascii'),'"', sep='')