Hello. I can't seem to figure out this problem's solution. I've read the editorial and I understand the first part but when the author says:

"To further optimize this solution, another transformation is needed. Ideally, we would like each ai to contribute to the answer independently of other values. And this can almost be achieved. Notice that the maximum returns 0 only if ai<ai−1 for any k, not just for k=1. This may require proof, but it is quite obvious."

I just don't get what this means. I also don't know what he's tryna do with the ci coefficient. I'd really appreciate it if someone here could explain it to me.