Apex domains cannot have CNAME records.
Question and response
Question
dig hosting.nic.ru. NS
Answer
hosting.nic.ru. 5 NS zdnsb2.nic.ru.
hosting.nic.ru. 5 NS zdnsb1.nic.ru.
Authority
The response has no authority records.
Additional
. 0 OPT ; payload 1232, xrcode 0, version 0, flags 0