There are 6 shapes on a 8x8 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 gray square at (1, 2): 2
Distance from target shape to red right_triangle at (1, 1): 3
Distance from target shape to brown square at (3, 7): 5
Distance from target shape to pink right_triangle at (1, 0): 4
Distance from target shape to purple right_triangle at (3, 6): 4
Closest shape is the gray square at (1, 2) with distance 2</think>

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