There are 4 shapes on a 10x10 grid. Which shape is closest to the purple 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: purple square at (3, 7)
Distance from target shape to orange square at (4, 8): 2
Distance from target shape to yellow right_triangle at (6, 5): 5
Distance from target shape to gray square at (7, 5): 6
Closest shape is the orange square at (4, 8) with distance 2</think>

<answer>(4, 8)</answer>