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

<answer>(6, 3)</answer>