input: Write a python function to calculate the Hamming Distance between two strings.
  assert HammingDistance("karolin", "kathrin") == 3
  assert HammingDistance("karolin", "kerstin") == 3
  assert HammingDistance("1011101", "1001001") == 2
  assert HammingDistance("2173896", "2233796") == 3
output: def HammingDistance(str1, str2):
      if len(str1) != len(str2):
          raise ValueError("Strings must be of the same length")
      return sum(el1 != el2 for el1, el2 in zip(str1, str2))