Apex domains cannot have CNAME records.
Question and response
Question
dig vimpelcom.ru. NS
Answer
vimpelcom.ru. 4 NS ns1.beelinegprs.ru.
vimpelcom.ru. 4 NS ns1.beeline.ru.
vimpelcom.ru. 4 NS ns2.beelinegprs.ru.
vimpelcom.ru. 4 NS ns2.beeline.ru.
Authority
The response has no authority records.
Additional
ns1.beeline.ru. 4 A 217.118.84.9
ns1.beelinegprs.ru. 4 A 217.118.66.243
ns2.beeline.ru. 4 A 217.118.84.65
ns2.beelinegprs.ru. 4 A 217.118.66.244
. 0 OPT ; payload 1232, xrcode 0, version 0, flags 0