There are 3 shapes on a 7x7 grid. Which shape is closest to the gray 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: gray square at (0, 1)
Distance from target shape to blue right_triangle at (0, 6): 5
Distance from target shape to red right_triangle at (3, 6): 8
Closest shape is the blue right_triangle at (0, 6) with distance 5</think>

<answer>(0, 6)</answer>