input: Write a function to calculate the dot product of two input lists. If the lengths of the input lists are not the same, return -1.
  assert dot_product([1, 2], [3, 4])==11
  assert dot_product([1], [2])==2
  assert dot_product([], [])==0
  assert dot_product([1, 2], [3])==-1
  assert dot_product([3, 4], [1, 2])==11
output: def dot_product(list1, list2):
      if len(list1) != len(list2):
          return -1
      return sum(x * y for x, y in zip(list1, list2))