Have a very very very simple question about pH

Question: What would be the pH of a solution with a hydroxide ion [OH-] concentration of 10^-12 M?

PLEASE EXPLAIN! the answer is pH of 2 and I am really confused... I thought it was pH of 12 and

I thought adding a base does the opposite, increasing OH− concentration and lowering H+ concentration.

Thx!

You are thinking it right but doing a little mistake.
Its the [OH] conc. not [H] conc.
So,pOH is 12
Now,as pH+pOH=14.
So,pH=14-pOH
pH=14-12=2.....:-)