Statement

Alessandro is a famous juggler and everyone loves him. He was asked to organize multiple shows, and he needs some help scheduling them. Alessandro needs to take part in N different shows, numbered from 0 to N-1. Each show must be assigned a day on which he performs it. Show i starts at a specific time A_i and ends at a specific time B_i of its assigned day. He has to decide the day to perform each show, note that Alessandro can decide to perform each show on a different day, so the intervals are allowed to overlap. Alessandro can perform two shows on the same day if the first show ends exactly at the time when the second show starts. Formally, he can perform shows i and j on the same day if B_i = A_j. He can also perform three or more shows on the same day if the first show ends exactly when the second show starts, the second show ends exactly when the third shows start, and so on. He may schedule the shows in any order...