There are 3 shapes on a 7x7 grid. Which shape is closest to the gray 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: gray rectangle at (3, 4)
Distance from target shape to pink square at (1, 2): 4
Distance from target shape to purple square at (6, 5): 4
Closest shape is the pink square at (1, 2) with distance 4</think>

<answer>(1, 2)</answer>