There are 5 shapes on a 6x6 grid. Which shape is closest to the gray trapezoid 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 trapezoid at (1, 5)
Distance from target shape to red rectangle at (3, 4): 3
Distance from target shape to yellow square at (5, 3): 6
Distance from target shape to blue square at (3, 2): 5
Distance from target shape to green trapezoid at (5, 1): 8
Closest shape is the red rectangle at (3, 4) with distance 3</think>

<answer>(3, 4)</answer>