| 1102 | Strange Dialog | Tetrahedron Team Online Contest May 2001 | 2951 | 166 |
| 1158 | Censored! | NEERC 2001 Northern Subregional | 970 | 505 |
| 1177 | Like Comparisons | USU Personal Contest 2002 | 389 | 1244 |
| 1297 | Palindrome | Spring School Contest 2004 | 6232 | 82 |
| 1354 | Palindrome. Again Palindrome | Spring School Contest 2005 | 3699 | 139 |
| 1423 | String Tale | Timus Top Coders: First Challenge | 2915 | 172 |
| 1517 | Freedom of Choice | Timus Top Coders: Third Challenge | 1892 | 249 |
| 1590 | Bacon’s Cipher | NEERC 2007 Eastern Subregional | 2327 | 190 |
| 1677 | Monkey at the Keyboard | Petrozavodsk Summer 2008. USU Contest | 247 | 1575 |
| 1684 | Jack's Last Word | USU Personal Contest 2009 | 1498 | 266 |
| 1713 | Key Substrings | NEERC 2009 Eastern Subregional | 604 | 622 |
| 1723 | Sandro's Book | Ural Regional School Programming Contest 2009 | 6182 | 62 |
| 1842 | Local Roots | Petrozavodsk Summer 2010. USU Contest | 39 | 6654 |
| 1937 | Davy Jones’s Organ | Ural FU Championship 2012 | 234 | 1209 |
| 1954 | Five Palindromes | Petrozavodsk Winter 2013. Kontur Cup. ChU 2013 Selection | 61 | 3938 |
| 1960 | Palindromes and Super Abilities | Petrozavodsk Winter 2013. Kontur Cup. ChU 2013 Selection | 638 | 431 |
| 2040 | Palindromes and Super Abilities 2 | Petrozavodsk Summer 2014. Ural FU Dandelion Contest | 274 | 859 |
| 2044 | 31 Palindromes | Petrozavodsk Summer 2014. Ural FU Dandelion Contest | 84 | 2595 |
| 2045 | Richness of words | Petrozavodsk Summer 2014. Ural FU Dandelion Contest | 518 | 462 |
| 2077 | Reductions | Qualification of Eastern Subregional 2015 | 18 | 7621 |
| 2118 | Cipher Message 4 | Petrozavodsk Summer 2018. umnik_team Contest | 89 | 1416 |
| 2131 | Open Cup | Later is better than never | 15 | 5425 |
| 2137 | Dynamic string complexity | Later is better than never | 13 | 5897 |
| 2168 | Runes in the Field | Ural School Programming Contest 2022 | 10 | 2691 |
