DHS NYJC Pre-NOI Contest 1 (0/600)

NYRCS: This will be done during the 12 Feb session :) Pls do not join before then! SHICC: This will be done soon during our session next week (date & time TBC) PLS DO NOT JOIN BEFORE THEN OR ELSE.... This contest is open book. However: 1. No AI 2. Don't tell each other solutions 3. No googling the problem itself The problems are ordered by increasing difficulty NOTE: The second problem is a hint for the third problem