| 1049 | Brave Balloonists | USU Local Contest. March 2000 | 5690 | 239 |
| 1086 | Cryptography | Spring School Contest 2001 | 11357 | 108 |
| 1091 | Tmutarakan Exams | USU Local Contest. March 2001 | 2337 | 496 |
| 1104 | Don’t Ask Woman about Her Age | Tetrahedron Team Online Contest May 2001 | 4811 | 93 |
| 1118 | Nontrivial Numbers | Autumn School Contest 2001 | 4400 | 102 |
| 1133 | Fibonacci Sequence | NEERC 2001 Central Subregional | 2054 | 219 |
| 1204 | Idempotents | USU Local Contest. March 2002 | 2003 | 226 |
| 1261 | Tips | Autumn School Contest 2003 | 1378 | 335 |
| 1286 | Starship Travel | USU Personal Contest 2004 | 677 | 680 |
| 1352 | Mersenne Primes | Spring School Contest 2005 | 3655 | 129 |
| 1355 | Bald Spot Revisited | Spring School Contest 2005 | 2182 | 216 |
| 1356 | Something Easier | Spring School Contest 2005 | 1352 | 347 |
| 1430 | Crime and Punishment | Timus Top Coders: First Challenge | 991 | 461 |
| 1456 | Jedi Riddle 2 | Timus Top Coders: Second Challenge | 590 | 757 |
| 1554 | Multiplicative Functions | Petrozavodsk Summer 2007. NSU Contest | 621 | 634 |
| 1560 | Elementary Symmetric Functions | Petrozavodsk Summer 2007. NSU Contest | 401 | 973 |
| 1698 | Square Country 5 | Petrozavodsk Winter 2009. USU Contest | 572 | 598 |
| 1748 | The Most Complex Number | Petrozavodsk Summer 2009. Ufa SATU Contest | 1245 | 255 |
| 1807 | Cartridges for Maxim | NEERC 2010 Eastern Subregional | 211 | 1337 |
| 2070 | Interesting Numbers | Ural Regional School Programming Contest 2015 | 776 | 197 |
| 2102 | Michael and Cryptography | Ural FU Junior Championship 2016 | 1003 | 126 |
| 2117 | Polyphemus' triples | University academic school olympiad in informatics 2019 | 142 | 455 |
| 2124 | Algebra on Segment | Petrozavodsk Summer 2018. t.me/umnik_team Contest | 33 | 1555 |
| 2138 | The Good, the Bad and the Ugly | Ural School Programming Contest 2019 | 514 | 108 |
