There are 4 shapes on a 5x5 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 (4, 2)
Distance from target shape to green square at (1, 0): 5
Distance from target shape to brown right_triangle at (4, 3): 1
Distance from target shape to blue right_triangle at (2, 3): 3
Closest shape is the brown right_triangle at (4, 3) with distance 1</think>

<answer>(4, 3)</answer>