There are 5 shapes on a 8x8 grid. Which shape is closest to the purple 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: purple rectangle at (6, 6)
Distance from target shape to cyan rectangle at (3, 7): 4
Distance from target shape to orange square at (1, 4): 7
Distance from target shape to yellow right_triangle at (6, 2): 4
Distance from target shape to pink rectangle at (5, 7): 2
Closest shape is the pink rectangle at (5, 7) with distance 2</think>

<answer>(5, 7)</answer>