There are 3 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 (4, 1)
Distance from target shape to orange rectangle at (2, 1): 2
Distance from target shape to yellow rectangle at (2, 4): 5
Closest shape is the orange rectangle at (2, 1) with distance 2</think>

<answer>(2, 1)</answer>