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

<answer>(3, 5)</answer>