Across a stream runs a row of eight stepping stones. On one side of the stream, on the first five stones, sit five girl lizards-Liza, Lizzie, Lottie, Lola, and Liz-and they want to get across to the other side. There's one empty stone in the middle. On the other side are three boy lizards, waiting to come across the other way-Lonnie, Leo, and Len. Only one lizard moves at a time. Any lizard may hop to the next stone if it is empty, or may hop over one lizard of the opposite sex onto an empty stone.
Can you get all the lizards across the river, and what's the smallest number of leaps?