Apex domains cannot have CNAME records.
Question and response
Question
dig citytelecom.ru. NS
Answer
citytelecom.ru. 5 NS ns10.hoster.ru.
citytelecom.ru. 5 NS ns11.hoster.ru.
Authority
The response has no authority records.
Additional
ns10.hoster.ru. 3 A 195.128.50.221
ns11.hoster.RU. 3 A 31.28.20.108
ns10.hoster.ru. 4 AAAA 2a00:13c0:201:0:0:0:0:2
ns11.hoster.RU. 4 AAAA 2a00:13c0:4e:4:0:0:0:3
. 0 OPT ; payload 1232, xrcode 0, version 0, flags 0