There are 4 shapes on a 8x8 grid. Which shape is closest to the green 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: green square at (3, 4)
Distance from target shape to yellow square at (0, 1): 6
Distance from target shape to red trapezoid at (7, 6): 6
Distance from target shape to cyan right_triangle at (0, 4): 3
Closest shape is the cyan right_triangle at (0, 4) with distance 3</think>

<answer>(0, 4)</answer>