There are 5 shapes on a 7x7 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 (0, 4)
Distance from target shape to blue rectangle at (4, 2): 6
Distance from target shape to cyan right_triangle at (1, 6): 3
Distance from target shape to purple trapezoid at (6, 4): 6
Distance from target shape to yellow rectangle at (4, 1): 7
Closest shape is the cyan right_triangle at (1, 6) with distance 3</think>

<answer>(1, 6)</answer>