Beta reducing $SS(SK)$ using SKI calculus

I have an expression to $beta$ – reduce and I managed to brute force it using lambda calculus. I was wondering though, if I could make it in less steps, than what I did, using SKI calculus. For example it is said, that $S$ takes 3 arguments so that $Sxyz = xz (yz)$, but in my case I only have 2 arguments at most, so I can’t really apply it.

Is there something I am not aware of, that allows us to use the combinators?