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 brown rectangle at (6, 1): 5
Distance from target shape to cyan square at (3, 7): 4
Distance from target shape to orange right_triangle at (1, 3): 4
Distance from target shape to pink right_triangle at (1, 1): 6
Closest shape is the cyan square at (3, 7) with distance 4</think>

<answer>(3, 7)</answer>