There are 6 shapes on a 7x7 grid. Which shape is closest to the blue 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: blue square at (2, 3)
Distance from target shape to red trapezoid at (4, 1): 4
Distance from target shape to cyan rectangle at (1, 2): 2
Distance from target shape to purple rectangle at (2, 4): 1
Distance from target shape to green rectangle at (1, 6): 4
Distance from target shape to yellow right_triangle at (2, 2): 1
Closest shape is the purple rectangle at (2, 4) with distance 1</think>

<answer>(2, 4)</answer>