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

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