There are 3 shapes on a 8x8 grid. Which shape is closest to the red square 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 square at (1, 3)
Distance from target shape to purple trapezoid at (4, 1): 5
Distance from target shape to orange square at (7, 7): 10
Closest shape is the purple trapezoid at (4, 1) with distance 5</think>

<answer>(4, 1)</answer>