you will have a client program (your own laptop or an instance in the cloud if you don't own a laptop). Your client program will send an upper bound and a lower bound to your server program in a cloud instance.
your server takes the lower and upper bound values, and returns the number of primes between these values.
your server also has a counter which starts before your for loop (which calls the function which finds prime numbers), and ends right after the for loop.
your server program needs to utilize all cores available to your cloud instance (has to be more than a single core). To do this make sure you use "multi-threading" in your server program.