Apex domains cannot have CNAME records.
Question and response
Question
dig QUANTUM.RU. NS
Answer
QUANTUM.RU. 5 NS ns1.QUANTUM.RU.
QUANTUM.RU. 5 NS ns.QUANTUM.RU.
Authority
The response has no authority records.
Additional
ns.QUANTUM.RU. 5 A 213.170.64.33
ns1.QUANTUM.RU. 5 A 213.170.65.33
. 0 OPT ; payload 1232, xrcode 0, version 0, flags 0