\item \self  Construct a Reduced Ordered Binary Decision Diagram (ROBDD) for the formula

$$f = (q \land \lnot s) \lor (s \land (\neg r \vee p)) \lor (p \land q \land r)$$

using \textit{variable order} $p < q < r < s$. Use complemented edges and a node for \texttt{true} as the only constant node. To simplify drawing, you may assume that \textit{dangling edges} point to the constant node. Write down all cofactors that you compute to obtain the final result and mark them in the graph.

% (q and not s) or (s and (not r or p)) or (p and q and r)