A digging week

Codeforces Global Round 31 last Friday wrapped up the 2025 Global Round series ( problems , results , top 5 on the left, analysis , serie standings that use the "sum all 3" instead of the actual "sum 2 best out of 3" scoring system). I spent way too much time on implementation and debugging once again, solved A-F1 and then decided not to go for even more standard-ish implementation in F2 and…