There are 4 shapes on a 7x7 grid. Which shape is closest to the blue 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: blue square at (4, 0)
Distance from target shape to purple trapezoid at (6, 6): 8
Distance from target shape to red trapezoid at (4, 3): 3
Distance from target shape to pink square at (5, 6): 7
Closest shape is the red trapezoid at (4, 3) with distance 3</think>

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