There are 6 shapes on a 8x8 grid. Which shape is closest to the red 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: red rectangle at (5, 5)
Distance from target shape to cyan rectangle at (4, 2): 4
Distance from target shape to gray rectangle at (1, 2): 7
Distance from target shape to yellow square at (1, 1): 8
Distance from target shape to green square at (7, 4): 3
Distance from target shape to brown rectangle at (7, 7): 4
Closest shape is the green square at (7, 4) with distance 3</think>

<answer>(7, 4)</answer>