There are 4 shapes on a 8x8 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 (1, 4)
Distance from target shape to pink square at (1, 5): 1
Distance from target shape to red right_triangle at (4, 0): 7
Distance from target shape to green right_triangle at (1, 3): 1
Closest shape is the pink square at (1, 5) with distance 1</think>

<answer>(1, 5)</answer>