input: 
  def dot_product(list1, list2):
      product = 0
      for i in range(len(list1)):
          product += (list1[i] * list2[i])
      return product
  
  # Example
  list1 = [1,2]
  list2 = [3,4]
  
  result = dot_product(list1, list2)
  print(result)
  # Output: 11
  
output:     if len(list1) != len(list2):
          raise ValueError("Lists must be of the same length")