| 1102 | Strange Dialog | Tetrahedron Team Online Contest May 2001 | 2860 | 168 |
| 1158 | Censored! | NEERC 2001 Northern Subregional | 959 | 502 |
| 1177 | Like Comparisons | USU Personal Contest 2002 | 383 | 1240 |
| 1297 | Palindrome | Spring School Contest 2004 | 6139 | 81 |
| 1354 | Palindrome. Again Palindrome | Spring School Contest 2005 | 3629 | 139 |
| 1423 | String Tale | Timus Top Coders: First Challenge | 2856 | 173 |
| 1517 | Freedom of Choice | Timus Top Coders: Third Challenge | 1810 | 255 |
| 1590 | Bacon’s Cipher | NEERC 2007 Eastern Subregional | 2272 | 190 |
| 1677 | Monkey at the Keyboard | Petrozavodsk Summer 2008. USU Contest | 243 | 1557 |
| 1684 | Jack's Last Word | USU Personal Contest 2009 | 1469 | 263 |
| 1713 | Key Substrings | NEERC 2009 Eastern Subregional | 593 | 615 |
| 1723 | Sandro's Book | Ural Regional School Programming Contest 2009 | 6057 | 61 |
| 1842 | Local Roots | Petrozavodsk Summer 2010. USU Contest | 36 | 6822 |
| 1937 | Davy Jones’s Organ | Ural FU Championship 2012 | 230 | 1176 |
| 1954 | Five Palindromes | Petrozavodsk Winter 2013. Kontur Cup. ChU 2013 Selection | 60 | 3808 |
| 1960 | Palindromes and Super Abilities | Petrozavodsk Winter 2013. Kontur Cup. ChU 2013 Selection | 615 | 426 |
| 2040 | Palindromes and Super Abilities 2 | Petrozavodsk Summer 2014. Ural FU Dandelion Contest | 266 | 834 |
| 2044 | 31 Palindromes | Petrozavodsk Summer 2014. Ural FU Dandelion Contest | 81 | 2530 |
| 2045 | Richness of words | Petrozavodsk Summer 2014. Ural FU Dandelion Contest | 502 | 450 |
| 2077 | Reductions | Qualification of Eastern Subregional 2015 | 18 | 7112 |
| 2118 | Cipher Message 4 | Petrozavodsk Summer 2018. umnik_team Contest | 83 | 1340 |
| 2131 | Open Cup | Later is better than never | 10 | 5998 |
| 2137 | Dynamic string complexity | Later is better than never | 9 | 6314 |
| 2168 | Runes in the Field | Ural School Programming Contest 2022 | 5 | 2444 |
