$ su -

apt-get install sudo

sudo vi /etc/sudoers

#

# This file MUST be edited with the 'visudo' command as root.

#

# Please consider adding local content in /etc/sudoers.d/ instead of

# directly modifying this file.

#

# See the man page for details on how to write a sudoers file.

#

Defaults|   env_reset

Defaults|   mail_badpass

Defaults|   secure_path="/usr/local/sbin:/usr/local/bin:/usr/sbin:/usr/bin:/sbin:/bin"

# Host alias specification

# User alias specification

# Cmnd alias specification

# User privilege specification

root|   ALL=(ALL:ALL) ALL

# Members of the admin group may gain root privileges

%admin ALL=(ALL) ALL

# Allow members of group sudo to execute any command

%sudo|  ALL=(ALL:ALL) ALL

# See sudoers() for more information on "#include" directives:

#includedir /etc/sudoers.d