Here you see a pool with six happy frogs. You must exchange the positions of the brown and green frogs, using the following rules:

• a frog can only jump to an empty water lily;
• a frog can only jump over at most one other frog, that has another color;
• a frog can only jump forward (so the green frogs jump right, and the brown frogs jump left).

The question: How can this be done?

A hint : Click on a frog to let it jump.

The answer: Click here!