If you look at universities most, even the best, only really need 3 to 4. I know people who started doing five and found it hard to keep up with all the work, but of course that depends on what your taking and how you manage your time as a person. It's really up to you, i would say look at universities if you have any remote idea of what you want to do and you will see for yourself.
You'll do well no matter what i'm sure.