There are 4 shapes on a 8x8 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 (5, 0)
Distance from target shape to purple right_triangle at (3, 7): 9
Distance from target shape to gray rectangle at (5, 2): 2
Distance from target shape to blue rectangle at (0, 4): 9
Closest shape is the gray rectangle at (5, 2) with distance 2</think>

<answer>(5, 2)</answer>