There are 4 shapes on a 6x6 grid. Which shape is closest to the gray square in terms of Manhattan distance? The final answer is the grid position of the closest shape like (row_index, column_index).
<think>Target shape: gray square at (0, 4)
Distance from target shape to orange right_triangle at (5, 1): 8
Distance from target shape to yellow square at (0, 0): 4
Distance from target shape to green rectangle at (2, 5): 3
Closest shape is the green rectangle at (2, 5) with distance 3</think>

<answer>(2, 5)</answer>