Conference Room Booking

You are given a list of time intervals representing the time slots during which various meetings are to be scheduled. Your task is to determine the minimum number of conference rooms required to host all the meetings without any conflicts. A meeting interval is represented as 'start end'. Input first line contains an integer n, the number of intervals, followed by n lines of start and end times. Output a single integer representing the minimum number of rooms needed. Example: Input: 3 09:00 10:00 09:30 11:00 11:00 12:00 Output: 2