How to set default input language in OS X Yosemite?

I want to make Russian my default keyboard input language, but OS X won't let me. Is there a hidden preference or something for this?

Solution 1:

In System preferences choose "keyboard"

Be sure the "Show input in menu in menu bar" is checked then click the "+" sign in the bottom left choose your language and keyboard type for the language and click "Add" then in your OS menu at the top right you will find and input menu where you can select "French" or whatever language you have chosen.

EDIT

Adding default language to the os

1. choose Language and Region in System Preferences
2. Click "+" in bottom left corner of preferences pain.
3. Choose your language
4. you will be prompted asking if you would like to make it your primary language , do that.
5. you may be prompted to add an input devices language
6. click keyboard preferences. It will prompt you to restart, again , do that.

good luck

Solution 2:

No, it doens't work like mcgrailm described at all. Actually + - are just to add and remove the language in a fixed sequence like MacOs wants. There is no way to set a default language. E.g. if I want to set German as default, always it comes behind chinese and British.