Ranking at depth 18
Model's reasoning and response:
To rank the states, we need to evaluate how close each state is to the goal state, which requires the first row of tiles to be painted in an alternating color pattern starting with black. Additionally, states where tiles are painted incorrectly should be ranked lower, and states where the robot is positioned optimally for the next move should be ranked higher.

### Evaluation of States:

1. **State 108**:
   - **Correctly Painted Tiles**: All tiles in the first row are painted correctly.
   - **Robot Position**: Robot1 is on tile_1-4, which is optimal for moving down to the next row.
   - **Paint Gun**: Holding black paint, ready for the next row.
   - **Ranking**: Best state as it meets the goal state requirements.

2. **State 101**:
   - **Correctly Painted Tiles**: All tiles in the first row are painted correctly.
   - **Robot Position**: Robot1 is on tile_1-4, ready to move down.
   - **Paint Gun**: Holding black paint, ready for the next row.
   - **Ranking**: Same as State 108, but slightly less optimal due to the paint gun color.

3. **State 102**:
   - **Correctly Painted Tiles**: All tiles in the first row are painted correctly.
   - **Robot Position**: Robot1 has moved down to tile_2-4, which is the correct next step.
   - **Paint Gun**: Holding white paint, which is not optimal for the next row.
   - **Ranking**: Slightly less optimal due to paint gun color.

4. **State 107**:
   - **Correctly Painted Tiles**: All tiles in the first row are painted correctly.
   - **Robot Position**: Robot1 has moved down to tile_2-4.
   - **Paint Gun**: Holding white paint, which is not optimal for the next row.
   - **Ranking**: Similar to State 102.

5. **State 103**:
   - **Correctly Painted Tiles**: All tiles in the first row are painted correctly.
   - **Robot Position**: Robot1 is on tile_1-3, not yet moved down.
   - **Paint Gun**: Holding white paint.
   - **Ranking**: Less optimal due to position and paint gun color.

6. **State 104**:
   - **Correctly Painted Tiles**: All tiles in the first row are painted correctly.
   - **Robot Position**: Robot1 is on tile_1-3, not yet moved down.
   - **Paint Gun**: Holding white paint.
   - **Ranking**: Similar to State 103.

7. **State 105**:
   - **Correctly Painted Tiles**: All tiles in the first row are painted correctly.
   - **Robot Position**: Robot1 is on tile_1-4, ready to move down.
   - **Paint Gun**: Holding black paint.
   - **Ranking**: Similar to State 101, but less optimal due to not moving down.

8. **State 106**:
   - **Correctly Painted Tiles**: All tiles in the first row are painted correctly.
   - **Robot Position**: Robot1 is on tile_1-3, not yet moved down.
   - **Paint Gun**: Holding white paint.
   - **Ranking**: Similar to State 103 and 104.

### Final Ranking:
```ranking
108, 101, 102, 107, 103, 104, 105, 106
```

Final ranking:
Rank 1: State ID 108
State Description: Tile_0-4 is now painted black. Robot1 remains on tile_1-4, holding black paint.

Rank 2: State ID 101
State Description: Robot1, still on tile_1-4, has changed its paint gun color from white to black.

Rank 3: State ID 102
State Description: Robot1 moves from tile_1-4 to tile_2-4, making tile_1-4 clear and occupying tile_2-4.

Rank 4: State ID 107
State Description: Robot1 moves from tile_1-4 to tile_2-4. Tile_1-4 becomes clear, and tile_2-4 is now occupied by Robot1.

Rank 5: State ID 103
State Description: Robot1 moves from tile_1-4 to tile_1-3, holding the white paint gun. Tile_1-4 becomes clear, and tile_1-3 is now occupied by Robot1.

Rank 6: State ID 104
State Description: Robot1 moves from tile_1-4 to tile_1-3, making tile_1-4 clear and occupying tile_1-3. Robot1 is still holding white paint.

Rank 7: State ID 105
State Description: Robot1 is now holding black paint while remaining on tile_1-4.

Rank 8: State ID 106
State Description: Robot1 moves from tile_1-4 to tile_1-3, making tile_1-4 clear and occupying tile_1-3. The robot is still holding the white paint gun.

