So, I'm wading through the practice problems in Davie's chapter on Lambda Calculus, and he throws this one at me:

So, I tried to do this just by substituting and following the rules (fortunately I had already calculated S (S S) and (S S)). But by about the third piece of paper I lost track of the parenthesis and gave up. I threw it into a lambda calculator which used 1079 steps to produce a result that was over 15 lines long.reduce the following λ-expression to normal form:

S (S S) (S S) (S S) S S

where S = λ x y z . x z (y z)

Now, likely Davie didn't intend to give me 5 hours of busy work, so presumably there is some pattern or short cut I am supposed to be seeing here. Does anyone have any insight they could share that would be beneficial to me here?