Apex domains cannot have CNAME records.
Question and response
Question
dig SAMPO.RU. NS
Answer
sampo.ru. 5 NS ns1.sampo.ru.
sampo.ru. 5 NS ns.sampo.ru.
Authority
The response has no authority records.
Additional
ns.sampo.RU. 5 A 217.77.52.252
ns1.sampo.ru. 5 A 217.77.53.237
. 0 OPT ; payload 1232, xrcode 0, version 0, flags 0