May Challenge 2013
Witua and Math, Tree Counting, Queries on tree again!, Password Cracking Challenge, Juno Puzzle for May, Name Reduction, Your Name is Mine, Field Trip, Matchsticks
June Challenge 2013
Dessert Wizard, Lapindromes, W String, To challenge or not, Predictopus, Count Special Matrices, Two k-Convex Polygons, Just Some Permutations 3, Collecting Magical Berries, Little Elephant and Mouses
August Challenge 2013
Little Elephant and Lemonade, Splitting Candies, Prime Distance On Tree, Deleting numbers, Sereja and Ballons, Chef and Segments, The Number Of Solutions, Save The Princess, Hello Hello, Music & Lyrics
December Challenge 2013
Lucy and the Flowers, Art in Digital Age, Cube Cakes, Chef and Codes, Petya and Sequence, Funny Marbles, Magic Pairs, Reign, Rectangular Queries, Query on a tree VI
