There are 4 shapes on a 8x8 grid. Which shape is closest to the gray 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: gray rectangle at (5, 7)
Distance from target shape to yellow square at (0, 5): 7
Distance from target shape to pink square at (3, 2): 7
Distance from target shape to green square at (4, 5): 3
Closest shape is the green square at (4, 5) with distance 3</think>

<answer>(4, 5)</answer>