There are 6 shapes on a 6x6 grid. Which shape is closest to the pink 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: pink right_triangle at (1, 3)
Distance from target shape to purple right_triangle at (1, 0): 3
Distance from target shape to blue rectangle at (5, 1): 6
Distance from target shape to cyan trapezoid at (0, 1): 3
Distance from target shape to brown rectangle at (4, 2): 4
Distance from target shape to green rectangle at (5, 5): 6
Closest shape is the purple right_triangle at (1, 0) with distance 3</think>

<answer>(1, 0)</answer>