Classroom Overlap

You are given a schedule of classes in a day, where each class is represented by a start and end time. Your task is to find how many classes overlap at any given time. The input consists of an integer n (the number of classes) followed by n pairs of integers (the start and end times of each class). Output the maximum number of overlapping classes at any point in time. Example: Input: 4 1 3 2 4 3 5 4 6 Output: 2