Attempt Number: 6
Error Message: Action not unique compared to other actions chosen from this state before. Choose a new action

Action Reasoning:
Since the robot is on tile_2-1 and holding black, it should paint the tile directly below (tile_3-1) to fulfill the goal state requirement for row 3. This aligns with the constraint that painting must occur below first.

New State Description:
- Robot Position and Paint:  - Robot1 is on tile_2-1, holding the color black.  - Tiles Status:  - Row 0: tile_0-1, tile_0-2, tile_0-3 are clear.  - Row 1: tile_1-1, tile_1-2, tile_1-3 are clear.  - Row 2: tile_2-1 is occupied by robot1, tile_2-2 and tile_2-3 are clear.  - Row 3: tile_3-1 is painted black, tile_3-2 and tile_3-3 are clear.- Available Colors:  - White and black are available for switching.

Action Chosen:
paint-down(robot1, tile_3-1, tile_2-1, black)
