I want to calculate the dot product using a Python Program. It is a part b of the original exercise. I need to use global variables for this program. Please note that the program does not need the zip function or any special functions. It needs to calculate using just the global variables. The instructions are as follows:

If possible, please also provide a sample test case to show how the program can be tested. The code needs to be in Python 3.5. I just need the part b of this question, I have the solution to part a.