There are 3 shapes on a 8x8 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 (2, 6)
Distance from target shape to gray right_triangle at (4, 5): 3
Distance from target shape to brown right_triangle at (0, 7): 3
Closest shape is the gray right_triangle at (4, 5) with distance 3</think>

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