Note: everthing before first left parenthesis is treated as a comment.
This problem hs 2 rockets and fuel is treated as a cargo that must be
loaded into a rocket for it to fire.

(London PLACE)
(Pgh PLACE)
(JFK PLACE)
(r1 ROCKET)
(r2 ROCKET)
(Kippers CARGO)
(mxf CARGO)
(avrim CARGO)
(x4 CARGO)
(x5 CARGO)
(x6 CARGO)
(x7 CARGO)
(x8 CARGO)
(x9 CARGO)
(f1 CARGO)
(f2 CARGO)
(f1 FUEL)
(f2 FUEL)

(preconds
(at r1 London)
(at r2 London)
(at mxf London)
(at Kippers London)
(at avrim London)
(at f1 London)
(at f2 London)
(at x4 London)
(at x5 London)
(at x6 London)
(at x7 London)
(at x8 London)
(at x9 London))

(effects
(at mxf Pgh)  
(at avrim Pgh)
(at Kippers Pgh)
(at x5 JFK)
(at x8 JFK)
(at x9 JFK))