There are 5 shapes on a 8x8 grid. Which shape is closest to the brown right_triangle in terms of Manhattan distance? The final answer is the grid position of the closest shape like (row_index, column_index).
<think>Target shape: brown right_triangle at (5, 1)
Distance from target shape to green rectangle at (4, 4): 4
Distance from target shape to gray trapezoid at (3, 3): 4
Distance from target shape to cyan right_triangle at (1, 7): 10
Distance from target shape to purple square at (5, 0): 1
Closest shape is the purple square at (5, 0) with distance 1</think>

<answer>(5, 0)</answer>