First, transport the sheep from the north shore to the south shore. At this time, there are only wolves and grass left on the north shore.

Then people go back to the north shore by boat and transport the grass to the south shore.

After arriving at the south bank, unload the grass, put on the sheep and return to the north bank.

Go to the north shore to unload the sheep and put the wolf on it, and carry the wolf to the south shore.

Unloaded on the south bank, where only wolves and grass were left.

Sail the boat to the north shore with no load, load the sheep and return to the south shore.