| 1049 | Brave Balloonists | USU Local Contest. March 2000 | 5471 | 239 |
| 1086 | Cryptography | Spring School Contest 2001 | 10629 | 111 |
| 1091 | Tmutarakan Exams | USU Local Contest. March 2001 | 2241 | 499 |
| 1104 | Don’t Ask Woman about Her Age | Tetrahedron Team Online Contest May 2001 | 4593 | 94 |
| 1118 | Nontrivial Numbers | Autumn School Contest 2001 | 4480 | 97 |
| 1133 | Fibonacci Sequence | NEERC 2001 Central Subregional | 2370 | 183 |
| 1204 | Idempotents | USU Local Contest. March 2002 | 1907 | 229 |
| 1261 | Tips | Autumn School Contest 2003 | 1305 | 342 |
| 1286 | Starship Travel | USU Personal Contest 2004 | 653 | 681 |
| 1352 | Mersenne Primes | Spring School Contest 2005 | 3508 | 130 |
| 1355 | Bald Spot Revisited | Spring School Contest 2005 | 2055 | 222 |
| 1356 | Something Easier | Spring School Contest 2005 | 1295 | 351 |
| 1430 | Crime and Punishment | Timus Top Coders: First Challenge | 945 | 467 |
| 1456 | Jedi Riddle 2 | Timus Top Coders: Second Challenge | 559 | 770 |
| 1554 | Multiplicative Functions | Petrozavodsk Summer 2007. NSU Contest | 598 | 629 |
| 1560 | Elementary Symmetric Functions | Petrozavodsk Summer 2007. NSU Contest | 376 | 990 |
| 1698 | Square Country 5 | Petrozavodsk Winter 2009. USU Contest | 545 | 593 |
| 1748 | The Most Complex Number | Petrozavodsk Summer 2009. Ufa SATU Contest | 1144 | 260 |
| 1807 | Cartridges for Maxim | NEERC 2010 Eastern Subregional | 196 | 1335 |
| 2070 | Interesting Numbers | Ural Regional School Programming Contest 2015 | 644 | 200 |
| 2102 | Michael and Cryptography | Ural FU Junior Championship 2016 | 875 | 115 |
| 2117 | Polyphemus' triples | University academic school olympiad in informatics 2019 | 56 | 635 |
| 2124 | Algebra on Segment | Petrozavodsk Summer 2018. t.me/umnik_team Contest | 15 | 1584 |
