There are 2 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, 1)
Distance from target shape to gray rectangle at (2, 3): 2
Closest shape is the gray rectangle at (2, 3) with distance 2</think>

<answer>(2, 3)</answer>