Merging Availability Windows

You are given a list of availability windows represented by intervals, where each interval consists of a start and an end time (in hours). You need to merge overlapping intervals and produce a list of distinct intervals that represent the combined availability. The intervals are given as a space-separated string. Print the merged intervals as a space-separated string. Example: Input: 9 12 11 15 16 18 10 14 Output: 9 15 16 18