| 1049 | Brave Balloonists | USU Local Contest. March 2000 | 6018 | 246 |
| 1086 | Cryptography | Spring School Contest 2001 | 12654 | 106 |
| 1091 | Tmutarakan Exams | USU Local Contest. March 2001 | 2429 | 521 |
| 1104 | Don’t Ask Woman about Her Age | Tetrahedron Team Online Contest May 2001 | 5194 | 94 |
| 1118 | Nontrivial Numbers | Autumn School Contest 2001 | 4755 | 103 |
| 1133 | Fibonacci Sequence | NEERC 2001 Central Subregional | 2201 | 222 |
| 1204 | Idempotents | USU Local Contest. March 2002 | 2153 | 228 |
| 1261 | Tips | Autumn School Contest 2003 | 1530 | 327 |
| 1286 | Starship Travel | USU Personal Contest 2004 | 755 | 662 |
| 1352 | Mersenne Primes | Spring School Contest 2005 | 3921 | 130 |
| 1355 | Bald Spot Revisited | Spring School Contest 2005 | 2415 | 211 |
| 1356 | Something Easier | Spring School Contest 2005 | 1721 | 296 |
| 1430 | Crime and Punishment | Timus Top Coders: First Challenge | 1071 | 463 |
| 1456 | Jedi Riddle 2 | Timus Top Coders: Second Challenge | 653 | 745 |
| 1554 | Multiplicative Functions | Petrozavodsk Summer 2007. NSU Contest | 688 | 636 |
| 1560 | Elementary Symmetric Functions | Petrozavodsk Summer 2007. NSU Contest | 465 | 934 |
| 1698 | Square Country 5 | Petrozavodsk Winter 2009. USU Contest | 614 | 634 |
| 1748 | The Most Complex Number | Petrozavodsk Summer 2009. Ufa SATU Contest | 1394 | 263 |
| 1807 | Cartridges for Maxim | NEERC 2010 Eastern Subregional | 230 | 1446 |
| 2070 | Interesting Numbers | Ural Regional School Programming Contest 2015 | 971 | 221 |
| 2102 | Michael and Cryptography | Ural FU Junior Championship 2016 | 1385 | 137 |
| 2117 | Polyphemus' triples | University academic school olympiad in informatics 2019 | 247 | 533 |
| 2124 | Algebra on Segment | Petrozavodsk Summer 2018. umnik_team Contest | 94 | 1298 |
| 2138 | The Good, the Bad and the Ugly | Ural School Programming Contest 2019 | 1213 | 103 |
