Goal: delight your customers by sending riders to pick and deliver their orders
  in less than 60 minutes (faster if you can).

  Hypothesis:
    - (x, y) coordinates are used to locate restaurants, customers and riders on a grid
    - the distance between x=0 and x=1 is 1000 meters (1 km)
    - the distance between two arbitrary (x,y) locations is the euclidean distance (straight line)
    - times are expressed in minutes
    - speeds are expressed in kilometers per hour (km/h)

  Note: some other hypothesis you can make to simplify the problem:
    - all customer orders are received at the same time (t=0)
    - all restaurants start cooking at the same time (t=0)
    - all riders start moving at the same time (t=0)
    - each restaurant can cook an infinite number of meals in parallel
    - each rider can carry an infinite amount of meals at the same time