| 1049 | Brave Balloonists | USU Local Contest. March 2000 | 5939 | 244 |
| 1086 | Cryptography | Spring School Contest 2001 | 12344 | 106 |
| 1091 | Tmutarakan Exams | USU Local Contest. March 2001 | 2376 | 520 |
| 1104 | Don’t Ask Woman about Her Age | Tetrahedron Team Online Contest May 2001 | 5083 | 94 |
| 1118 | Nontrivial Numbers | Autumn School Contest 2001 | 4660 | 103 |
| 1133 | Fibonacci Sequence | NEERC 2001 Central Subregional | 2165 | 221 |
| 1204 | Idempotents | USU Local Contest. March 2002 | 2120 | 227 |
| 1261 | Tips | Autumn School Contest 2003 | 1488 | 329 |
| 1286 | Starship Travel | USU Personal Contest 2004 | 728 | 671 |
| 1352 | Mersenne Primes | Spring School Contest 2005 | 3855 | 130 |
| 1355 | Bald Spot Revisited | Spring School Contest 2005 | 2368 | 211 |
| 1356 | Something Easier | Spring School Contest 2005 | 1697 | 293 |
| 1430 | Crime and Punishment | Timus Top Coders: First Challenge | 1051 | 462 |
| 1456 | Jedi Riddle 2 | Timus Top Coders: Second Challenge | 640 | 742 |
| 1554 | Multiplicative Functions | Petrozavodsk Summer 2007. NSU Contest | 678 | 627 |
| 1560 | Elementary Symmetric Functions | Petrozavodsk Summer 2007. NSU Contest | 459 | 919 |
| 1698 | Square Country 5 | Petrozavodsk Winter 2009. USU Contest | 603 | 624 |
| 1748 | The Most Complex Number | Petrozavodsk Summer 2009. Ufa SATU Contest | 1363 | 259 |
| 1807 | Cartridges for Maxim | NEERC 2010 Eastern Subregional | 227 | 1402 |
| 2070 | Interesting Numbers | Ural Regional School Programming Contest 2015 | 936 | 211 |
| 2102 | Michael and Cryptography | Ural FU Junior Championship 2016 | 1322 | 130 |
| 2117 | Polyphemus' triples | University academic school olympiad in informatics 2019 | 213 | 528 |
| 2124 | Algebra on Segment | Petrozavodsk Summer 2018. t.me/umnik_team Contest | 91 | 1144 |
| 2138 | The Good, the Bad and the Ugly | Ural School Programming Contest 2019 | 1054 | 99 |
