I’m not understanding what they mean by ‘chains’. As in, for the first sample input, when i connect all the cows that can be paired up(with a semicircle because it’s in geogebra):

as a follow up, when we compute “ub[i]” (from the official solution), can’t we just use a pointer for this, since ub[] will always move leftwards?
and when they state 𝚍𝚙[i][j]=𝚍𝚙[i+1][j], how do we ensure cow i is paired up? (For example, say we want to leave i + 1 unpaired but i + 2 is too far away? Or, there are an even number of cows that are already paired?)