There are 5 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 (4, 1)
Distance from target shape to gray square at (2, 3): 4
Distance from target shape to red square at (2, 2): 3
Distance from target shape to brown trapezoid at (2, 0): 3
Distance from target shape to yellow rectangle at (5, 1): 1
Closest shape is the yellow rectangle at (5, 1) with distance 1</think>

<answer>(5, 1)</answer>