Apex domains cannot have CNAME records.
Question and response
Question
dig h.mchost.ru. NS
Answer
h.mchost.ru. 5 NS nserver1.mchost.ru.
h.mchost.ru. 5 NS nserver2.mchost.ru.
Authority
The response has no authority records.
Additional
. 0 OPT ; payload 1232, xrcode 0, version 0, flags 0