| 1102 | Strange Dialog | Tetrahedron Team Online Contest May 2001 | 2890 | 168 |
| 1158 | Censored! | NEERC 2001 Northern Subregional | 963 | 504 |
| 1177 | Like Comparisons | USU Personal Contest 2002 | 386 | 1241 |
| 1297 | Palindrome | Spring School Contest 2004 | 6178 | 81 |
| 1354 | Palindrome. Again Palindrome | Spring School Contest 2005 | 3669 | 139 |
| 1423 | String Tale | Timus Top Coders: First Challenge | 2885 | 172 |
| 1517 | Freedom of Choice | Timus Top Coders: Third Challenge | 1854 | 251 |
| 1590 | Bacon’s Cipher | NEERC 2007 Eastern Subregional | 2292 | 190 |
| 1677 | Monkey at the Keyboard | Petrozavodsk Summer 2008. USU Contest | 245 | 1563 |
| 1684 | Jack's Last Word | USU Personal Contest 2009 | 1484 | 264 |
| 1713 | Key Substrings | NEERC 2009 Eastern Subregional | 596 | 620 |
| 1723 | Sandro's Book | Ural Regional School Programming Contest 2009 | 6114 | 61 |
| 1842 | Local Roots | Petrozavodsk Summer 2010. USU Contest | 37 | 6789 |
| 1937 | Davy Jones’s Organ | Ural FU Championship 2012 | 230 | 1199 |
| 1954 | Five Palindromes | Petrozavodsk Winter 2013. Kontur Cup. ChU 2013 Selection | 61 | 3834 |
| 1960 | Palindromes and Super Abilities | Petrozavodsk Winter 2013. Kontur Cup. ChU 2013 Selection | 628 | 427 |
| 2040 | Palindromes and Super Abilities 2 | Petrozavodsk Summer 2014. Ural FU Dandelion Contest | 268 | 849 |
| 2044 | 31 Palindromes | Petrozavodsk Summer 2014. Ural FU Dandelion Contest | 82 | 2566 |
| 2045 | Richness of words | Petrozavodsk Summer 2014. Ural FU Dandelion Contest | 509 | 455 |
| 2077 | Reductions | Qualification of Eastern Subregional 2015 | 17 | 7603 |
| 2118 | Cipher Message 4 | Petrozavodsk Summer 2018. umnik_team Contest | 83 | 1412 |
| 2131 | Open Cup | Later is better than never | 10 | 6336 |
| 2137 | Dynamic string complexity | Later is better than never | 9 | 6669 |
| 2168 | Runes in the Field | Ural School Programming Contest 2022 | 5 | 2937 |
