| 1049 | Brave Balloonists | USU Local Contest. March 2000 | 5881 | 242 |
| 1086 | Cryptography | Spring School Contest 2001 | 12069 | 106 |
| 1091 | Tmutarakan Exams | USU Local Contest. March 2001 | 2344 | 519 |
| 1104 | Don’t Ask Woman about Her Age | Tetrahedron Team Online Contest May 2001 | 5020 | 93 |
| 1118 | Nontrivial Numbers | Autumn School Contest 2001 | 4601 | 103 |
| 1133 | Fibonacci Sequence | NEERC 2001 Central Subregional | 2140 | 220 |
| 1204 | Idempotents | USU Local Contest. March 2002 | 2099 | 226 |
| 1261 | Tips | Autumn School Contest 2003 | 1453 | 332 |
| 1286 | Starship Travel | USU Personal Contest 2004 | 716 | 673 |
| 1352 | Mersenne Primes | Spring School Contest 2005 | 3815 | 129 |
| 1355 | Bald Spot Revisited | Spring School Contest 2005 | 2298 | 214 |
| 1356 | Something Easier | Spring School Contest 2005 | 1668 | 294 |
| 1430 | Crime and Punishment | Timus Top Coders: First Challenge | 1039 | 460 |
| 1456 | Jedi Riddle 2 | Timus Top Coders: Second Challenge | 628 | 745 |
| 1554 | Multiplicative Functions | Petrozavodsk Summer 2007. NSU Contest | 658 | 634 |
| 1560 | Elementary Symmetric Functions | Petrozavodsk Summer 2007. NSU Contest | 453 | 915 |
| 1698 | Square Country 5 | Petrozavodsk Winter 2009. USU Contest | 597 | 616 |
| 1748 | The Most Complex Number | Petrozavodsk Summer 2009. Ufa SATU Contest | 1340 | 257 |
| 1807 | Cartridges for Maxim | NEERC 2010 Eastern Subregional | 224 | 1382 |
| 2070 | Interesting Numbers | Ural Regional School Programming Contest 2015 | 885 | 211 |
| 2102 | Michael and Cryptography | Ural FU Junior Championship 2016 | 1232 | 130 |
| 2117 | Polyphemus' triples | University academic school olympiad in informatics 2019 | 188 | 535 |
| 2124 | Algebra on Segment | Petrozavodsk Summer 2018. t.me/umnik_team Contest | 79 | 1165 |
| 2138 | The Good, the Bad and the Ugly | Ural School Programming Contest 2019 | 929 | 100 |
