There are 6 shapes on a 7x7 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 (4, 1)
Distance from target shape to pink square at (1, 4): 6
Distance from target shape to brown square at (2, 1): 2
Distance from target shape to blue trapezoid at (6, 5): 6
Distance from target shape to orange trapezoid at (4, 5): 4
Distance from target shape to green square at (4, 6): 5
Closest shape is the brown square at (2, 1) with distance 2</think>

<answer>(2, 1)</answer>