This sequent is provable. \begin{logicproof}{2} \lnot p \imp q & \prem \\ \lnot \lnot \lnot q \land r & \prem \\ \lnot \lnot \lnot q & $\ande{1} 2$ \\ \lnot q & $\negnege 3$ \\ \lnot\lnot p & $\MT 1,4$ \\ p & $\negnege 5$ \\ p \land \lnot \lnot \lnot q & $\andi 6,3$ \end{logicproof}