There are 6 shapes on a 8x8 grid. Which shape is closest to the gray 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: gray rectangle at (4, 5)
Distance from target shape to purple rectangle at (4, 0): 5
Distance from target shape to red trapezoid at (1, 1): 7
Distance from target shape to cyan trapezoid at (6, 7): 4
Distance from target shape to yellow square at (0, 3): 6
Distance from target shape to pink rectangle at (1, 5): 3
Closest shape is the pink rectangle at (1, 5) with distance 3</think>

<answer>(1, 5)</answer>