There are 5 shapes on a 10x10 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, 9)
Distance from target shape to brown rectangle at (5, 9): 4
Distance from target shape to purple square at (5, 7): 6
Distance from target shape to green right_triangle at (3, 4): 7
Distance from target shape to yellow rectangle at (9, 1): 16
Closest shape is the brown rectangle at (5, 9) with distance 4</think>

<answer>(5, 9)</answer>