There are 5 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 yellow square at (2, 4): 5
Distance from target shape to red right_triangle at (5, 0): 2
Distance from target shape to pink rectangle at (4, 1): 2
Distance from target shape to brown square at (0, 1): 6
Closest shape is the red right_triangle at (5, 0) with distance 2</think>

<answer>(5, 0)</answer>