There are 3 shapes on a 7x7 grid. Which shape is closest to the blue 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: blue right_triangle at (5, 1)
Distance from target shape to pink right_triangle at (6, 3): 3
Distance from target shape to green rectangle at (2, 5): 7
Closest shape is the pink right_triangle at (6, 3) with distance 3</think>

<answer>(6, 3)</answer>