There are 3 shapes on a 6x6 grid. Which shape is closest to the gray 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: gray square at (1, 3)
Distance from target shape to brown trapezoid at (0, 4): 2
Distance from target shape to pink square at (2, 4): 2
Closest shape is the brown trapezoid at (0, 4) with distance 2</think>

<answer>(0, 4)</answer>