Attempt Number: 4
Error Message: Action not unique compared to other actions chosen from this state before. Choose a new action

Action Reasoning:
To continue with the given plan, we need to move the fast elevator fast1 currently at floor n3 to floor n4 so that passengers p2 and p3 can board.

New State Description:
- fast0: At floor n0, 0/2 passengers.- fast1: At floor n4, 0/2 passengers.- slow0-0: At floor n0, 0/1 passengers.- slow1-0: At floor n3, 0/1 passengers.- p0: On floor n0.- p1: On floor n1.- p2: On floor n4.- p3: On floor n4.- p4: On floor n1.- p5: On floor n3.

Action Chosen:
(move-up-fast fast1 n3 n4)
