May Challenge 2013
Witua and Math, Juno Puzzle for May, Name Reduction, Your Name is Mine, Field Trip, Matchsticks
June Challenge 2013
Two k-Convex Polygons, Lapindromes, W String, To challenge or not, Predictopus, Count Special Matrices, Dessert Wizard, Just Some Permutations 3, Collecting Magical Berries, Little Elephant and Mouses
August Challenge 2013
Hello Hello, Splitting Candies, Prime Distance On Tree, Deleting numbers, Sereja and Ballons, Chef and Segments, The Number Of Solutions, Save The Princess, Music & Lyrics, Little Elephant and Lemonade
September Challenge 2013
Little Elephant and Exams, Merciless Chef, Cool Guys, Chef and Integers , Project Spoon, CAO Stage-1, CAO Stage-2, To Queue or not to Queue, Two Roads, Sereja and Snake
