As usual, 10 days from the first Friday of the month (link to the contest; starting time), a Long Challenge contest takes place. As usual again, there are 10 problems — 9 with subtask scoring and one challenge problem with relative scoring. Feel free to participate!

The people involved are:

• setters: Furko, TonySnark, EG0R, aangairbender, Rebryk, Cenadar, CherryTree, KaiZeR, Tehnar

• tester: iscsi

• editorialist: myself

• language verifier: RahulArora

• translators: CherryTree — Russian, Team VNOI — Vietnamese, huzecong — Mandarin

• contest admin: PraveenDhinwa