There are 3 shapes on a 8x8 grid. Which shape is closest to the yellow 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: yellow rectangle at (0, 6)
Distance from target shape to purple rectangle at (7, 1): 12
Distance from target shape to green square at (3, 7): 4
Closest shape is the green square at (3, 7) with distance 4</think>

<answer>(3, 7)</answer>