There are 6 shapes on a 8x8 grid. Which shape is closest to the orange 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: orange rectangle at (7, 1)
Distance from target shape to red trapezoid at (1, 4): 9
Distance from target shape to pink right_triangle at (7, 6): 5
Distance from target shape to gray rectangle at (6, 4): 4
Distance from target shape to blue rectangle at (7, 3): 2
Distance from target shape to green right_triangle at (2, 3): 7
Closest shape is the blue rectangle at (7, 3) with distance 2</think>

<answer>(7, 3)</answer>