A Funny Game.
See how quickly you can switch the frogs to the opposite side of the pond.
Frogs can only jump onto an empty rock. A frog can jump over one frog to an empty rock—but only over one.
Frogs cannot jump back, only forward. It’s easy to tell which way they can go—they face the way they want to jump.
When all the frogs have reached the other side of the pond, you win!