There are 5 shapes on a 9x9 grid. Which shape is closest to the gray 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: gray square at (6, 6)
Distance from target shape to blue trapezoid at (3, 3): 6
Distance from target shape to yellow right_triangle at (2, 8): 6
Distance from target shape to red square at (4, 5): 3
Distance from target shape to green trapezoid at (3, 6): 3
Closest shape is the red square at (4, 5) with distance 3</think>

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