In the middle of the ocean, there are two islands; one of the truth-telling tribe and one of the lying tribe. One day, you hear news of a secret treasure being buried on one of the islands and set sail to one of the islands with ambitious eyes. However, you do not know which island you have come to, and therefore ask one of the natives. The native says, "There exists treasure on this island if and only if I am telling the truth". Is there treasure on the island, and which tribe does this island belong to?