Problem A1: Perfectly Balanced - Chapter 1
F - Confluence
E - Sequence Matching
E - Throne
A - Dodecagon
B - Reversible Cards
Codeforces Round #354 (Div. 2) C. Vasya and String
Codeforces Round #355 (Div. 2) C. Vanya and Label
Codeforces Round #360 (Div. 1) A. NP-Hard Problem
Helvetic Coding Contest 2016 online mirror (teams, unrated) C2. Brain Network (medium)