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

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