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

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