Hamming distance, dened to be the number of bit positions that are different between two bit strings, is used to measure the error that is introduced when data is sent over a network. For example, suppose we sent the bit sequence 011100110001 over a network, but the destination received 011000110101 instead. To measure the transmission error, we can find the Hamming distance between the two sequences by lining them up as follows: Sent: 011100110001 Received: 011000110101 Since the bit sequences are different in two positions, the Hamming distance is 2. Write a function hamming(bits1, bits2) that returns the Hamming distance between the two given bit strings. Do not assume that the two strings have the same length.