There are 6 shapes on a 7x7 grid. Which shape is closest to the yellow 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: yellow square at (3, 6)
Distance from target shape to pink rectangle at (5, 0): 8
Distance from target shape to purple rectangle at (3, 2): 4
Distance from target shape to green right_triangle at (2, 0): 7
Distance from target shape to brown trapezoid at (5, 4): 4
Distance from target shape to gray right_triangle at (1, 4): 4
Closest shape is the purple rectangle at (3, 2) with distance 4</think>

<answer>(3, 2)</answer>