The longest (s. t)-path problem on supergrid graphs is known to be NP-complete. However. the complexity of this problem on supergrid graphs with or without holes is still unknown. https://www.bekindtopets.com/mega-pick-Silbrade-Braid-Reinforced-Silicone-Tubing-1-4-ID-x-520-OD-x-1-hot-grab/