Three fisherman were fishing on a secluded island. The fish briskly gobbled the bait; the fisherman were so absorbed that they did not notice that night had come and did not realize till too late what a mountain of fish they had hooked. So they had to spend the night on the island. Two fisherman quickly fell asleep, each nestled down under his boat, but the third had insomnia and decided to go home. He did not wake his comrades, but divided all the fish into three parts. There proved to be one extra fish. After a moment's thought, he threw it into the water, took his hare, and went home.

In the middle of the night, the second fisherman woke up. He did not know that the first fisherman had already left and also divided all the fish into three and, as before, there was one fish left over. As before, the fisherman threw the extra fish in the water, took his share, and went home.

By early morning, the third fisherman awoke. He did not notice that the other two fisherman had left, so he too divided all the fish into three and, as before, there was one fish left over. As did his comrades before him, the fisherman threw the extra fish in the water, took his share, and went home.

Determine the least number of fish that the fisherman could have caught.

Without googling 'Dirac'.