There are 4 shapes on a 10x10 grid. Which shape is closest to the blue 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: blue rectangle at (8, 1)
Distance from target shape to yellow rectangle at (6, 3): 4
Distance from target shape to purple rectangle at (3, 9): 13
Distance from target shape to brown trapezoid at (3, 5): 9
Closest shape is the yellow rectangle at (6, 3) with distance 4</think>

<answer>(6, 3)</answer>