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

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