There are 5 shapes on a 7x7 grid. Which shape is closest to the gray right_triangle 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 right_triangle at (6, 6)
Distance from target shape to pink trapezoid at (5, 4): 3
Distance from target shape to yellow square at (6, 0): 6
Distance from target shape to red square at (4, 0): 8
Distance from target shape to brown trapezoid at (1, 0): 11
Closest shape is the pink trapezoid at (5, 4) with distance 3</think>

<answer>(5, 4)</answer>