Answer: An enolizable ketone (or its enolate) and an α,β‑unsaturated carbonyl compound (a Michael acceptor, e.g. methyl vinyl ketone).
Explanation: The enolizable ketone forms an enolate that performs a Michael addition to the α,β‑unsaturated carbonyl; the resulting adduct then cyclizes by an intramolecular aldol condensation and dehydration to give a cyclohexenone (the Robinson annulation product).