There are 6 shapes on a 6x6 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 (5, 1)
Distance from target shape to green square at (3, 3): 4
Distance from target shape to gray rectangle at (5, 2): 1
Distance from target shape to cyan right_triangle at (0, 5): 9
Distance from target shape to red rectangle at (1, 4): 7
Distance from target shape to pink square at (4, 0): 2
Closest shape is the gray rectangle at (5, 2) with distance 1</think>

<answer>(5, 2)</answer>