There are 4 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 (7, 6)
Distance from target shape to yellow square at (4, 3): 6
Distance from target shape to brown rectangle at (0, 4): 9
Distance from target shape to green rectangle at (2, 8): 7
Closest shape is the yellow square at (4, 3) with distance 6</think>

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