There are 5 shapes on a 6x6 grid. Which shape is closest to the red 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: red square at (2, 5)
Distance from target shape to pink right_triangle at (1, 4): 2
Distance from target shape to cyan square at (5, 1): 7
Distance from target shape to green rectangle at (4, 0): 7
Distance from target shape to purple rectangle at (2, 3): 2
Closest shape is the pink right_triangle at (1, 4) with distance 2</think>

<answer>(1, 4)</answer>