There are 6 shapes on a 4x4 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 (1, 3)
Distance from target shape to red trapezoid at (0, 1): 3
Distance from target shape to cyan rectangle at (3, 0): 5
Distance from target shape to yellow rectangle at (0, 3): 1
Distance from target shape to gray square at (2, 3): 1
Distance from target shape to brown rectangle at (2, 2): 2
Closest shape is the yellow rectangle at (0, 3) with distance 1</think>

<answer>(0, 3)</answer>