There are 5 shapes on a 8x8 grid. Which shape is closest to the purple 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: purple square at (2, 1)
Distance from target shape to green rectangle at (6, 3): 6
Distance from target shape to orange rectangle at (1, 3): 3
Distance from target shape to brown right_triangle at (2, 0): 1
Distance from target shape to yellow right_triangle at (6, 6): 9
Closest shape is the brown right_triangle at (2, 0) with distance 1</think>

<answer>(2, 0)</answer>