   0: Ahmed arrives
   0: Bette arrives
   0: Carlos arrives
   0: Ahmed starts service
   0: Bette starts service
   5: Ahmed leaves
   5: Carlos starts service
   5: Bette leaves
  10: Carlos leaves

   0: Dave arrives
   0: Eve arrives
   0: Frank arrives
   0: Dave starts service
   0: Eve starts service
   5: Dave leaves
   5: Frank starts service
   5: Eve leaves
  10: Frank leaves
