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

<answer>(5, 6)</answer>