doubt about how to interpret/understand the groundtruth.txt

[Salvador]

Hi guys, 

I have downloded the dataset called ball3.

The ground is:

m178,174,38,46,14,11,25,15,21,19,17,22,15,25,12,27,10,29,8,31,6,33,5,33,4,35,3,35,3,35,2,37,1,568,1,37,1,37,1,36,3,35,3,35,3,34,5,33,5,33,5,33,5,32,7,31,7,30,9,28,11,26,13,23,16,18,22,13,16

How do you interpret/understand that bunch of points?

Thanks