There are 4 shapes on a 7x7 grid. Which shape is closest to the gray 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: gray square at (4, 5)
Distance from target shape to purple rectangle at (4, 6): 1
Distance from target shape to pink trapezoid at (4, 2): 3
Distance from target shape to brown trapezoid at (2, 2): 5
Closest shape is the purple rectangle at (4, 6) with distance 1</think>

<answer>(4, 6)</answer>