| 1049 | Brave Balloonists | USU Local Contest. March 2000 | 5622 | 240 |
| 1086 | Cryptography | Spring School Contest 2001 | 11206 | 109 |
| 1091 | Tmutarakan Exams | USU Local Contest. March 2001 | 2305 | 500 |
| 1104 | Don’t Ask Woman about Her Age | Tetrahedron Team Online Contest May 2001 | 4775 | 93 |
| 1118 | Nontrivial Numbers | Autumn School Contest 2001 | 4374 | 102 |
| 1133 | Fibonacci Sequence | NEERC 2001 Central Subregional | 2028 | 220 |
| 1204 | Idempotents | USU Local Contest. March 2002 | 1988 | 226 |
| 1261 | Tips | Autumn School Contest 2003 | 1361 | 337 |
| 1286 | Starship Travel | USU Personal Contest 2004 | 673 | 680 |
| 1352 | Mersenne Primes | Spring School Contest 2005 | 3631 | 129 |
| 1355 | Bald Spot Revisited | Spring School Contest 2005 | 2157 | 217 |
| 1356 | Something Easier | Spring School Contest 2005 | 1342 | 348 |
| 1430 | Crime and Punishment | Timus Top Coders: First Challenge | 987 | 460 |
| 1456 | Jedi Riddle 2 | Timus Top Coders: Second Challenge | 586 | 757 |
| 1554 | Multiplicative Functions | Petrozavodsk Summer 2007. NSU Contest | 617 | 633 |
| 1560 | Elementary Symmetric Functions | Petrozavodsk Summer 2007. NSU Contest | 396 | 977 |
| 1698 | Square Country 5 | Petrozavodsk Winter 2009. USU Contest | 569 | 596 |
| 1748 | The Most Complex Number | Petrozavodsk Summer 2009. Ufa SATU Contest | 1237 | 254 |
| 1807 | Cartridges for Maxim | NEERC 2010 Eastern Subregional | 207 | 1345 |
| 2070 | Interesting Numbers | Ural Regional School Programming Contest 2015 | 755 | 197 |
| 2102 | Michael and Cryptography | Ural FU Junior Championship 2016 | 970 | 125 |
| 2117 | Polyphemus' triples | University academic school olympiad in informatics 2019 | 132 | 453 |
| 2124 | Algebra on Segment | Petrozavodsk Summer 2018. t.me/umnik_team Contest | 32 | 1478 |
| 2138 | The Good, the Bad and the Ugly | Ural School Programming Contest 2019 | 448 | 113 |
