Apex domains cannot have CNAME records.
Question and response
Question
dig VALFMAN.RU. NS
Answer
VALFMAN.RU. 5 NS edna.ns.cloudflare.com.
VALFMAN.RU. 5 NS ed.ns.cloudflare.com.
Authority
The response has no authority records.
Additional
. 0 OPT ; payload 1232, xrcode 0, version 0, flags 0