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 (2, 3)
Distance from target shape to pink square at (0, 5): 4
Distance from target shape to yellow right_triangle at (2, 1): 2
Distance from target shape to red rectangle at (0, 3): 2
Distance from target shape to gray square at (1, 2): 2
Distance from target shape to blue rectangle at (4, 0): 5
Closest shape is the yellow right_triangle at (2, 1) with distance 2</think>

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