Hello Codeforces!

Our team is actively preparing for the upcoming ICPC Regional Contest. Unlike World Finals, Regional problem sets usually have a different dynamic and difficulty curve. We want to align our practice with the actual target level. I would really appreciate insights from alumni / experienced participants on the following questions regarding problem types: 1. Typically, out of 10–12 problems, how many are considered "must-solve"? 2. Which topics appear most frequently in Regional Contests?

Any breakdown of typical Regional problem sets or advice on topic prioritization would be extremely helpful! Thanks in advance!