Attempt Number: 2
Error Message: The action and resulting child state have already been explored.

Action Reasoning:
The last action taken was "paint-up," which means the next step should be to move the robot horizontally if there are unpainted tiles in the row above. Since the robot is currently at tile_1-4 and the row above (row 0) still has unpainted tiles, the robot should move left to tile_1-3. This will position the robot to paint the next unpainted tile in the sequence.

New State Description:
Robot1 moves from tile_1-4 to tile_1-3. Tile_1-4 is now clear, and tile_1-3 is occupied by Robot1, which is holding a white paint gun.

Action Chosen:
left(robot1, tile_1-4, tile_1-3)
