C37 Surprise Surprise Surprise Surprise

It was strange, wasn't it, that the rolling stone should increase its speed, even though it was not a slope?

In fact, the size of the rolling stone did not occupy the entire maze, but its width was just right so that there was no way to retreat. However, the height had not reached the top, and there was still a large space left. If one was careful, even an adult could pass through there