There are 3 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 (1, 5)
Distance from target shape to pink trapezoid at (3, 4): 3
Distance from target shape to orange right_triangle at (1, 2): 3
Closest shape is the pink trapezoid at (3, 4) with distance 3</think>

<answer>(3, 4)</answer>