Three jackals and three coyotes are on a trek across the Mokalani Plateau when they come to a river filled with carnivorous fish. There is a rowboat in sight, and the party decides to use it. (Both species are known for their cleverness.) However, the boat is too small to hold any more than two of the group at a time, so they must traverse the river in successive crossings. There is one hitch, though: The jackals must not outnumber the coyotes at any time, in any place. For example, if two jackals, and only one coyote are together on the western side of the river, this jackals will overpower, kill, and eat the coyote. It’s okay to have an equal number of each, and it’s also okay to have more coyotes than jackals in a given place since neither poses a danger to the coyotes, and the coyotes do not pose a threat to the jackals. The trick here is to use one small rowboat, a lot of sweat, and a little brainpower to ensure the coyotes’ safety while both groups cross the river.

Determine the minimum number of river crossings.