Hi, I am interested in applications for top Maths Summer camps in the US next summer (PROMYS, SUMaC, HCCSIM, ROSS). How do I go about building a suitable portfolio to submit as well as prepare for the selection psets, I have heard they are usually proof-based rather than computational and I have no experience in proof based maths. I have self studied basic olympiad content before however no significant Olympiad experience/awards so far as well. Any help is appreciated :). P.S. I am entering JC2 (senior year) in January 2025 (based in Singapore)