08-21 CodeForces #664F - Boboniu and String

08-21 CodeForces #664E - Boboniu Walks on Graph

08-21 CodeForces #664D - Boboniu Chats with Du

08-21 Codeforces #664 C Boboniu and Bit Operations

08-02 Codeforces Round #659 (Div. 2) B2 - Koa and the Beach (Hard Version)

07-08 Educational Codeforces Round 89 (Rated for Div. 2) E. Two Arrays

07-07 Codeforces Round #654 (Div. 2) E Asterism