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

<answer>(5, 3)</answer>