There are 5 shapes on a 7x7 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 (1, 4)
Distance from target shape to brown rectangle at (1, 3): 1
Distance from target shape to blue right_triangle at (0, 3): 2
Distance from target shape to orange right_triangle at (3, 3): 3
Distance from target shape to yellow trapezoid at (3, 6): 4
Closest shape is the brown rectangle at (1, 3) with distance 1</think>

<answer>(1, 3)</answer>