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

<answer>(5, 4)</answer>