F - Xor Shift
E - Bichromization
Codeforces Round 262 (Div. 2) C. Present
Codeforces Round 265 (Div. 1) A. No to Palindromes!
Codeforces Round 266 (Div. 2) C. Number of Ways
Codeforces Round 267 (Div. 2) C. George and Job
Codeforces Round 269 (Div. 2) C. MUH and House of Cards
F - Modularness
F - Removing Robots
C - ThREE