There are 4 shapes on a 6x6 grid. Which shape is closest to the gray rectangle in terms of Manhattan distance? The final answer is the grid position of the closest shape like (row_index, column_index).
<think>Target shape: gray rectangle at (5, 2)
Distance from target shape to green right_triangle at (1, 2): 4
Distance from target shape to pink rectangle at (0, 3): 6
Distance from target shape to yellow trapezoid at (4, 5): 4
Closest shape is the green right_triangle at (1, 2) with distance 4</think>

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