Logical Game - Change the Places of the Frogs

Aim of the game:
Change the places of the yellow and red frogs, i.e. arrange the yellow frogs on the right and the red ones on the left.

How many moves do you need?
Could you think of a rule, with which to calculate the number of moves of yellow and red frogs in dependence with the amount of yellow and red frogs?

In order to start the game, push the green button in the bottom.

You could define the number of yellow and red frogs.