There are 3 shapes on a 8x8 grid. Which shape is closest to the green 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: green rectangle at (0, 7)
Distance from target shape to red right_triangle at (7, 1): 13
Distance from target shape to pink square at (4, 6): 5
Closest shape is the pink square at (4, 6) with distance 5</think>

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