Apex domains cannot have CNAME records.
Question and response
Question
dig merlion.RU. NS
Answer
merlion.ru. 1 NS ns2.merlion.ru.
merlion.ru. 1 NS ns1.merlion.ru.
Authority
The response has no authority records.
Additional
ns1.merlion.ru. 1 A 185.65.148.123
ns2.merlion.ru. 1 A 185.65.149.123
. 0 OPT ; payload 1232, xrcode 0, version 0, flags 0