There are 2 shapes on a 7x7 grid. Which shape is closest to the red 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: red right_triangle at (5, 0)
Distance from target shape to purple square at (6, 3): 4
Closest shape is the purple square at (6, 3) with distance 4</think>

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