There are 5 shapes on a 6x6 grid. Which shape is closest to the brown 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: brown rectangle at (3, 1)
Distance from target shape to pink square at (5, 1): 2
Distance from target shape to cyan rectangle at (0, 2): 4
Distance from target shape to yellow trapezoid at (0, 3): 5
Distance from target shape to red square at (1, 3): 4
Closest shape is the pink square at (5, 1) with distance 2</think>

<answer>(5, 1)</answer>