There are 4 shapes on a 7x7 grid. Which shape is closest to the yellow 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: yellow rectangle at (6, 4)
Distance from target shape to orange trapezoid at (2, 1): 7
Distance from target shape to brown right_triangle at (5, 1): 4
Distance from target shape to pink trapezoid at (3, 0): 7
Closest shape is the brown right_triangle at (5, 1) with distance 4</think>

<answer>(5, 1)</answer>