There are 3 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 (0, 5)
Distance from target shape to gray right_triangle at (6, 4): 7
Distance from target shape to red square at (7, 6): 8
Closest shape is the gray right_triangle at (6, 4) with distance 7</think>

<answer>(6, 4)</answer>