Apex domains cannot have CNAME records.
Question and response
Question
dig K66.RU. NS
Answer
k66.ru. 5 NS ns1.telenet.ru.
k66.ru. 5 NS ns2.telenet.ru.
Authority
The response has no authority records.
Additional
ns1.telenet.RU. 5 A 87.224.128.4
ns2.telenet.RU. 5 A 90.157.0.4
. 0 OPT ; payload 1232, xrcode 0, version 0, flags 0