| 1049 | Brave Balloonists | USU Local Contest. March 2000 | 5547 | 240 |
| 1086 | Cryptography | Spring School Contest 2001 | 10946 | 110 |
| 1091 | Tmutarakan Exams | USU Local Contest. March 2001 | 2275 | 500 |
| 1104 | Don’t Ask Woman about Her Age | Tetrahedron Team Online Contest May 2001 | 4702 | 93 |
| 1118 | Nontrivial Numbers | Autumn School Contest 2001 | 4294 | 103 |
| 1133 | Fibonacci Sequence | NEERC 2001 Central Subregional | 2414 | 183 |
| 1204 | Idempotents | USU Local Contest. March 2002 | 1952 | 227 |
| 1261 | Tips | Autumn School Contest 2003 | 1335 | 339 |
| 1286 | Starship Travel | USU Personal Contest 2004 | 666 | 679 |
| 1352 | Mersenne Primes | Spring School Contest 2005 | 3576 | 130 |
| 1355 | Bald Spot Revisited | Spring School Contest 2005 | 2113 | 219 |
| 1356 | Something Easier | Spring School Contest 2005 | 1315 | 351 |
| 1430 | Crime and Punishment | Timus Top Coders: First Challenge | 964 | 465 |
| 1456 | Jedi Riddle 2 | Timus Top Coders: Second Challenge | 572 | 765 |
| 1554 | Multiplicative Functions | Petrozavodsk Summer 2007. NSU Contest | 609 | 631 |
| 1560 | Elementary Symmetric Functions | Petrozavodsk Summer 2007. NSU Contest | 385 | 988 |
| 1698 | Square Country 5 | Petrozavodsk Winter 2009. USU Contest | 553 | 600 |
| 1748 | The Most Complex Number | Petrozavodsk Summer 2009. Ufa SATU Contest | 1187 | 258 |
| 1807 | Cartridges for Maxim | NEERC 2010 Eastern Subregional | 204 | 1330 |
| 2070 | Interesting Numbers | Ural Regional School Programming Contest 2015 | 701 | 200 |
| 2102 | Michael and Cryptography | Ural FU Junior Championship 2016 | 899 | 125 |
| 2117 | Polyphemus' triples | University academic school olympiad in informatics 2019 | 111 | 451 |
| 2124 | Algebra on Segment | Petrozavodsk Summer 2018. t.me/umnik_team Contest | 25 | 1493 |
| 2138 | The Good, the Bad and the Ugly | Ural School Programming Contest 2019 | 292 | 139 |
