Help Me Cross the River

I have been traveling across the country with my wolf, a sheep, and sack of grain. We have traveled a long way and finally reach the river. The ferry is broke and current is too strong to wade across.

The ferryman tells me I may use the smaller raft, but it cannot hold much weight. Only two items may be on the raft at any time.

I must get across with my wolf, the sheep, and the sack of grain. The four of us cannot all be on the raft at once, so I must make the trip across in stages.

If I leave the sheep with the grain, it will eat the grain. If I leave the wolf with the sheep, it will eat the sheep.

How do I get all items and myself across the river without losing any of the items?