How to change a natural deduction proof into a tree proof

Question

I'm working on this : $$\dashv(p \ \land q) \to (( \ r \to p)\ \land \ (r \to q))$$ And a solution is this :

1    assume p & q.
2      assume r.
3        p.                                                &E1 1
4      therefore r => p.                                   =>I 2,3
5      assume r.
6        q.                                                &E2 1
7      therefore r => q.                                   =>I 5,6
8      (r => p) & (r => q).                                &I 4,7
9    therefore p & q => (r => p) & (r => q).               =>I 1,8

Now I'm not able to understand, due to my ignorance, how to convert this into a tree proof? Maybe this question is so idiotic, but I have been trying for 1 hour and nothing. I hope someone helps me.

Answer 1

\begin{align} \cfrac{\cfrac {\cfrac{\cfrac{\cfrac{[p \land q]^2}{[r]^1} }{p \qquad \qquad q } \land \text {-E}} {(r \to p) \quad (r \to q)} \to \text {-I}_1}{(r \to p) \land (r \to q)}\land \text {-I}}{(p \land q) \to ((r \to p) \land (r \to q))}\to \text {-I}_2 \end{align}