For almost every other routine task in programming, I would argue that it really doesn't matter if your int is 32 bits wide or 64 bits wide. Why go through the trouble of insisting on int32_t or int64_t? It probably doesn't matter for the things you are counting.
Some programmers will say "Well, we should use int64_t here because int32_t might overflow!" OK, so why weren't you checking for overflow if it was an expected case? int64_t might overflow too, are you checking after every operation? Probably not. "OK, let's use uint64_t then, now we get 2x as many numbers!" Now you have other overflow (and subtraction) problems to handle.
Nowadays, I just use int and move on with my life. It's one of those lessons from experience: "When I was younger, I used int and char because I didn't know any better. When I was older, I created this complex, elaborate type system because I knew better. Now that I'm wise, I just use int and char."