There are 5 shapes on a 8x8 grid. Which shape is closest to the red 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: red rectangle at (6, 1)
Distance from target shape to gray trapezoid at (0, 1): 6
Distance from target shape to cyan rectangle at (6, 5): 4
Distance from target shape to blue trapezoid at (5, 4): 4
Distance from target shape to yellow trapezoid at (3, 3): 5
Closest shape is the cyan rectangle at (6, 5) with distance 4</think>

<answer>(6, 5)</answer>