14.04 - Error when sudo apt-get upgrade

I run Ubuntu 14.04 LTS. When I type sudo apt-get upgrade into the terminal I get this error message.

The following packages have unmet dependencies.
 cups : Depends: libc-bin (>= 2.13)
E: Unmet dependencies. Try using -f.

How can I force upgrade?

It says using the flag -f. That's an option. But you can also use this:

sudo apt-get update && sudo apt-get dist-upgrade