There are 5 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 (6, 1)
Distance from target shape to pink right_triangle at (2, 5): 8
Distance from target shape to green right_triangle at (0, 0): 7
Distance from target shape to gray right_triangle at (0, 4): 9
Distance from target shape to purple rectangle at (2, 2): 5
Closest shape is the purple rectangle at (2, 2) with distance 5</think>

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