Maximum Time Range

You're only able to stay in the hotel if an event is running. Can you find and print the maximum time ranges that you can stay in the hotel?

In this challenge, instead of avoiding overlapping times, you want them!

See if you can find an O(n log n) solution.

I/O Format

The input is the same as the last challenge. Find the optimal range of times of events and print each rnage like this: [start , end].