(refuel plane1)
(fly-slow plane1 city0 city4)
(board person6 plane1 city4)
(fly-slow plane1 city4 city2)
(board person3 plane1 city2)
(debark person6 plane1 city2)
(fly-slow plane1 city2 city1)
(board person1 plane1 city1)
(refuel plane1)
(debark person3 plane1 city1)
(fly-fast plane1 city1 city0)
(debark person1 plane1 city0)
(fly-slow plane1 city0 city3)
; cost = 13 (unit cost)
