Silly Stop

The busy accountants of the Ministry of Silly Walks need to get back to their office but not colliding with colleagues can be a challenge if every one takes their profession serious. Help them prevent collisions by stopping people to let others go past.

Rules: Use "A" to stop all yellow clerks and "D" to stop all blue clerks.

For each clerk reachin the other side of the screen you get 1 point for each clerk in a collision you get -1 point. 
Get the most points before time runs out.