There are 4 shapes on a 9x9 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 (3, 6)
Distance from target shape to pink right_triangle at (6, 8): 5
Distance from target shape to green square at (5, 3): 5
Distance from target shape to brown rectangle at (5, 2): 6
Closest shape is the pink right_triangle at (6, 8) with distance 5</think>

<answer>(6, 8)</answer>