lambda calculus with church numerals

Question

today I found this term in our exercises: ((^fx.f(f(f x)) ^gy.g(g y )) ^z.z + 1) (0)

I am quit unaware how to solve this type of question. I know this is the church numeral 3 , 2 , the identity function +1 and zero. But for my understanding it lacks an operator like +-*/ as ex.

(λmn.m (succ n)) to connect two church numerals?

Some hints will be greatly appreciated.