There are 5 shapes on a 6x6 grid. Which shape is closest to the blue rectangle in terms of Manhattan distance? The final answer is the grid position of the closest shape like (row_index, column_index).
<think>Target shape: blue rectangle at (4, 5)
Distance from target shape to brown rectangle at (5, 2): 4
Distance from target shape to purple right_triangle at (3, 3): 3
Distance from target shape to gray trapezoid at (4, 2): 3
Distance from target shape to red trapezoid at (2, 0): 7
Closest shape is the purple right_triangle at (3, 3) with distance 3</think>

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