GOAL SITUATION:  
• We want to move cars so that:  
  – curb_3 ends up with car_3 on it.  
  – curb_2 ends up with car_2 on it.  
  – curb_1 ends up with car_1 on it.  
  – curb_0 ends up with car_0 on it.  

The goal is to make sure these cars reach their final destination from their initial locations.