There are 4 shapes on a 8x8 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 (3, 1)
Distance from target shape to orange trapezoid at (1, 4): 5
Distance from target shape to cyan square at (7, 0): 5
Distance from target shape to yellow trapezoid at (2, 1): 1
Closest shape is the yellow trapezoid at (2, 1) with distance 1</think>

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