There are 4 shapes on a 6x6 grid. Which shape is closest to the gray 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: gray square at (5, 4)
Distance from target shape to pink right_triangle at (0, 4): 5
Distance from target shape to red trapezoid at (0, 5): 6
Distance from target shape to cyan right_triangle at (1, 5): 5
Closest shape is the pink right_triangle at (0, 4) with distance 5</think>

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