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 (5, 5)
Distance from target shape to orange trapezoid at (4, 0): 6
Distance from target shape to cyan right_triangle at (4, 3): 3
Distance from target shape to yellow right_triangle at (4, 5): 1
Closest shape is the yellow right_triangle at (4, 5) with distance 1</think>

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