Installing mariadb 10.2 in a fresh system shows error

I followed this link for installing mariadb-server 10.2 .
*https://downloads.mariadb.org/mariadb/repositories/#mirror=23Media&distro=Debian&distro_release=jessie--jessie&version=10.2*

i have added repo.list and keys.But ended up with the following error message

• Unable to set password for the MariaDB "root" user. An error occurred while setting the password for the MariaDB administrative user. This may have happened because the account already has a password, or because of a communication problem with the MariaDB server.You should check the account's password after the package installation*

But mariadb-server 10.0, 10.1 are installing and working fine .