There are 6 shapes on a 6x6 grid. Which shape is closest to the yellow 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: yellow rectangle at (2, 1)
Distance from target shape to gray rectangle at (4, 3): 4
Distance from target shape to cyan trapezoid at (3, 4): 4
Distance from target shape to orange square at (5, 5): 7
Distance from target shape to green right_triangle at (3, 5): 5
Distance from target shape to brown rectangle at (1, 2): 2
Closest shape is the brown rectangle at (1, 2) with distance 2</think>

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