There are 4 shapes on a 7x7 grid. Which shape is closest to the purple 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: purple rectangle at (0, 0)
Distance from target shape to red rectangle at (1, 0): 1
Distance from target shape to pink right_triangle at (3, 6): 9
Distance from target shape to cyan rectangle at (5, 5): 10
Closest shape is the red rectangle at (1, 0) with distance 1</think>

<answer>(1, 0)</answer>