There are 5 shapes on a 7x7 grid. Which shape is closest to the red 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: red square at (4, 1)
Distance from target shape to purple rectangle at (6, 2): 3
Distance from target shape to blue right_triangle at (2, 6): 7
Distance from target shape to green square at (6, 4): 5
Distance from target shape to brown trapezoid at (2, 3): 4
Closest shape is the purple rectangle at (6, 2) with distance 3</think>

<answer>(6, 2)</answer>