Humans and wolves

Three humans, one big wolf and two small wolves are to cross a river:

• Only humans and the big wolf can row the boat.
• At all times, the number of humans on either side of the river must be greater or equal to the number of wolves on that side. (Or else the humans will be eaten by the wolves!)
• The boat only has room for 2 (wolves or humans).
• wolves can jump out of the boat when it's banked.