I don't use Mint but it looks like you deleted an official package, which not a good thing to do.
The good news is that you get it back. Download this:
http://packages.linuxmint.com/pool/m..._8.4.1_all.deb
then navigate to the folder you have downloaded it to, probably
then use
Code:
sudo apt update
sudo apt install mintsystem_8.4.1_all.deb
and in the future be careful about what you're doing.