There are 3 shapes on a 4x4 grid. Which shape is closest to the pink 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: pink square at (3, 3)
Distance from target shape to blue right_triangle at (2, 0): 4
Distance from target shape to purple right_triangle at (2, 3): 1
Closest shape is the purple right_triangle at (2, 3) with distance 1</think>

<answer>(2, 3)</answer>