You have a small boat and you need to cross a river with three items: a wolf, a lamb, and a bale of hay. You can only take yourself plus one item at a time across the river. The problem is, you cannot leave the wolf alone with the lamb, or the wolf will eat the lamb. Also, you cannot leave the lamb alone with the bale of hay, or the lamb will eat the hay. How do you get all three items across the river?