How to solve phpmyadmin reconfiguration problem?

Question

MySQL

Friends, Ubuntu OS 16.04. I do the command dpkg-reconfigure phpmyadmin
I choose:
reinstall database: yes
Unix-Socket
database name: phpmyadmin
mysql database user: root
set application password: ***
name of the database administrative user: root
web-server: I don’t choose anything, I have nginx

And mysql said error
: ERROR 1045 (28000): Access denied for user 'root'@'localhost' (using password: YES)