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

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