Hello to all. I've (Trofimenko:)) solved this problem.

In my program I used constant MAXM=5000. I've got WA5. When I changed MAXM to 6000 I've got WA too. But when I changed maxm to 60000 I've got AC. It's so stupid...

The set contains at least one and at most 99999 segments!
What's means of your MAXM???   The number of segments?  If yes,you are wrong without doubt!

No, I was using it to limit M which should be <=5000