There are 3 shapes on a 10x10 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 (1, 8)
Distance from target shape to purple square at (4, 5): 6
Distance from target shape to green trapezoid at (9, 7): 9
Closest shape is the purple square at (4, 5) with distance 6</think>

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