There are 5 shapes on a 8x8 grid. Which shape is closest to the green 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: green square at (4, 4)
Distance from target shape to gray trapezoid at (2, 6): 4
Distance from target shape to cyan square at (0, 6): 6
Distance from target shape to red rectangle at (3, 1): 4
Distance from target shape to pink trapezoid at (1, 3): 4
Closest shape is the gray trapezoid at (2, 6) with distance 4</think>

<answer>(2, 6)</answer>