I'm just out of highschool and will be starting an advanced mathematics course in University (NSW, Australia). I'm unsure what each course consists of specifically, and all I've really heard about that will be in it is "discrete mathematics". It's vital that I get good marks on average throughout the first year, so I thought I would start early with self-study. What book(s) do you guys recommend? Note I took extension 2 mathematics in highschool (the highest level available) so I'm already proficient in quite a few topics such as single-variable calculus, trigonometry, complex numbers, polynomials etc. Thanks in advance for any suggestions.