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 orange trapezoid at (1, 4): 5
Distance from target shape to gray right_triangle at (2, 1): 3
Distance from target shape to pink rectangle at (2, 3): 3
Closest shape is the gray right_triangle at (2, 1) with distance 3</think>

<answer>(2, 1)</answer>