| 1049 | Brave Balloonists | USU Local Contest. March 2000 | 5439 | 239 |
| 1086 | Cryptography | Spring School Contest 2001 | 10533 | 111 |
| 1091 | Tmutarakan Exams | USU Local Contest. March 2001 | 2229 | 498 |
| 1104 | Don’t Ask Woman about Her Age | Tetrahedron Team Online Contest May 2001 | 4554 | 94 |
| 1118 | Nontrivial Numbers | Autumn School Contest 2001 | 4440 | 97 |
| 1133 | Fibonacci Sequence | NEERC 2001 Central Subregional | 2348 | 183 |
| 1204 | Idempotents | USU Local Contest. March 2002 | 1892 | 229 |
| 1261 | Tips | Autumn School Contest 2003 | 1287 | 344 |
| 1286 | Starship Travel | USU Personal Contest 2004 | 647 | 683 |
| 1352 | Mersenne Primes | Spring School Contest 2005 | 3476 | 130 |
| 1355 | Bald Spot Revisited | Spring School Contest 2005 | 2027 | 223 |
| 1356 | Something Easier | Spring School Contest 2005 | 1280 | 353 |
| 1430 | Crime and Punishment | Timus Top Coders: First Challenge | 936 | 468 |
| 1456 | Jedi Riddle 2 | Timus Top Coders: Second Challenge | 554 | 771 |
| 1554 | Multiplicative Functions | Petrozavodsk Summer 2007. NSU Contest | 596 | 625 |
| 1560 | Elementary Symmetric Functions | Petrozavodsk Summer 2007. NSU Contest | 375 | 984 |
| 1698 | Square Country 5 | Petrozavodsk Winter 2009. USU Contest | 543 | 588 |
| 1748 | The Most Complex Number | Petrozavodsk Summer 2009. Ufa SATU Contest | 1124 | 261 |
| 1807 | Cartridges for Maxim | NEERC 2010 Eastern Subregional | 194 | 1328 |
| 2070 | Interesting Numbers | Ural Regional School Programming Contest 2015 | 628 | 197 |
| 2102 | Michael and Cryptography | Ural FU Junior Championship 2016 | 839 | 114 |
| 2117 | Polyphemus' triples | University academic school olympiad in informatics 2019 | 29 | 936 |
