Apex domains cannot have CNAME records.
Question and response
Question
dig CITICTEL-CPC.RU. NS
Answer
CITICTEL-CPC.RU. 1 NS ns2.citictel-cpc.ru.
CITICTEL-CPC.RU. 1 NS ns1.citictel-cpc.ru.
Authority
The response has no authority records.
Additional
ns1.citictel-cpc.ru. 1 A 212.65.65.1
ns2.citictel-cpc.ru. 1 A 213.152.152.1
ns1.citictel-cpc.ru. 1 AAAA 2a01:6e0:0:0:0:0:0:1
ns2.citictel-cpc.ru. 1 AAAA 2a01:6e0:1:0:0:0:0:1
. 0 OPT ; payload 1232, xrcode 0, version 0, flags 0