There are 3 shapes on a 6x6 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, 1)
Distance from target shape to purple trapezoid at (0, 2): 5
Distance from target shape to green square at (4, 0): 1
Closest shape is the green square at (4, 0) with distance 1</think>

<answer>(4, 0)</answer>