There are 4 shapes on a 8x8 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 (6, 3)
Distance from target shape to red trapezoid at (6, 7): 4
Distance from target shape to purple square at (5, 3): 1
Distance from target shape to orange right_triangle at (2, 4): 5
Closest shape is the purple square at (5, 3) with distance 1</think>

<answer>(5, 3)</answer>