Current State ID: 0
Current State Description: We have a building with floors labeled 0 through 4 (n0 to n4). Each floor nX is considered “above” any floor nY where X < Y, meaning n0 < n1 < n2 < n3 < n4 in ascending order.

There are four elevators:

1. **fast0**, a fast elevator currently at floor 0 (n0). It has 0 passengers right now and has a maximum capacity of 2 passengers. It can reach all floors from 0 to 4 (n0 to n4).

2. **fast1**, another fast elevator, currently at floor 3 (n3). It holds 0 passengers at the moment and can also hold up to 2 passengers. It can serve all floors from 0 to 4 (n0 to n4).

3. **slow0-0**, a slow elevator currently at floor 1 (n1). It has 0 passengers right now and has a maximum capacity of 1 passenger. It can reach floors 0, 1, and 2 (n0 to n2).

4. **slow1-0**, another slow elevator, currently at floor 3 (n3). It holds 0 passengers at the moment and can also hold up to 1 passenger. It can serve floors 2, 3, and 4 (n2 to n4).

We have six passengers on specific floors:

- **p0** is on floor 1 (n1).
- **p1** is on floor 1 (n1).
- **p2** is on floor 4 (n4).
- **p3** is on floor 4 (n4).
- **p4** is on floor 1 (n1).
- **p5** is on floor 3 (n3).

Travel costs are as follows:

- Using a slow elevator costs 6 units per floor. For example, going from n0 to n1 (or n1 to n2) costs 6. Longer jumps (e.g., n0 to n2) cost 7 units.
- Using the fast elevator between any of its reachable floors (e.g., n0 to n1 or n1 to n2) costs 4 units per floor. Longer jumps (e.g., n0 to n3) cost 10 units.

The total cost starts at 0.

Child State ID: 1
Action Taken: move-up-fast(fast0, n0, n1)
State Description: Fast elevator fast0 is now at floor 1 with 0/2 passengers. Fast elevator fast1 remains at floor 3 with 0/2 passengers. Slow elevator slow0-0 is still at floor 1 with 0/1 passengers. Slow elevator slow1-0 is at floor 3 with 0/1 passengers. Passengers p0, p1, and p4 are on floor 1. Passenger p5 is on floor 3. Passengers p2 and p3 are on floor 4.

Child State ID: 2
Action Taken: board(p0, slow0-0, n1, 0, 1)
State Description: - Elevator **fast0** is still at floor 0 (n0), empty with a maximum capacity of 2.- Elevator **fast1** remains at floor 3 (n3), empty with a maximum capacity of 2.- Elevator **slow0-0** is at floor 1 (n1), now holding passenger p0 with a capacity of 1.- Elevator **slow1-0** stays at floor 3 (n3), empty with a maximum capacity of 1.- Passenger **p0** is on board slow0-0 at floor 1.- Passenger **p1** is still on floor 1 (n1).- Passenger **p2** remains on floor 4 (n4).- Passenger **p3** stays on floor 4 (n4).- Passenger **p4** is still on floor 1 (n1).- Passenger **p5** remains on floor 3 (n3).

Child State ID: 3
Action Taken: board(p5, fast1, n3, 0, 1)
State Description: - Fast0 is at floor 0 with 0 passengers (max capacity 2).- Fast1 is at floor 3 with 1 passenger (max capacity 2).- Slow0-0 is at floor 1 with 0 passengers (max capacity 1).- Slow1-0 is at floor 3 with 0 passengers (max capacity 1).- Passenger p0 is on floor 1.- Passenger p1 is on floor 1.- Passenger p2 is on floor 4.- Passenger p3 is on floor 4.- Passenger p4 is on floor 1.- Passenger p5 is aboard fast1.- Travel cost is still 0 as no elevator has moved yet.

