There are 4 shapes on a 7x7 grid. Which shape is closest to the brown 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: brown rectangle at (6, 4)
Distance from target shape to cyan trapezoid at (2, 3): 5
Distance from target shape to blue square at (0, 4): 6
Distance from target shape to yellow right_triangle at (4, 3): 3
Closest shape is the yellow right_triangle at (4, 3) with distance 3</think>

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