There are 3 shapes on a 7x7 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 (5, 1)
Distance from target shape to pink right_triangle at (5, 6): 5
Distance from target shape to gray rectangle at (6, 3): 3
Closest shape is the gray rectangle at (6, 3) with distance 3</think>

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