There are 2 shapes on a 4x4 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 (2, 3)
Distance from target shape to gray trapezoid at (3, 1): 3
Closest shape is the gray trapezoid at (3, 1) with distance 3</think>

<answer>(3, 1)</answer>