There are 4 shapes on a 10x10 grid. Which shape is closest to the brown rectangle 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 rectangle at (4, 9)
Distance from target shape to gray rectangle at (1, 9): 3
Distance from target shape to purple right_triangle at (1, 8): 4
Distance from target shape to blue square at (2, 8): 3
Closest shape is the gray rectangle at (1, 9) with distance 3</think>

<answer>(1, 9)</answer>