Codeforces Beta Round 33 (Codeforces format) D. Knights
Codeforces Beta Round 34 (Div. 2) E. Collisions
School Team Contest 1 (Winter Computer School 2010/11) A. C*++ Calculations
School Team Contest 1 (Winter Computer School 2010/11) E. What Has Dirichlet Got to Do with That?
Codeforces Beta Round 42 (Div. 2) D. Journey
Number game
Innocent Swaps and His Emotions
Micro and Matrix
Counting stars
Jumping Tokens