There are 5 shapes on a 4x4 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 (0, 3)
Distance from target shape to pink rectangle at (1, 1): 3
Distance from target shape to brown right_triangle at (0, 0): 3
Distance from target shape to yellow trapezoid at (2, 1): 4
Distance from target shape to cyan right_triangle at (3, 3): 3
Closest shape is the pink rectangle at (1, 1) with distance 3</think>

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