Social Network Separation

In a social network, users can follow each other to form groups. You will be given a set of follow relationships between users. Your task is to determine how many separate groups of users exist. A group is defined as a set of users where each user can reach every other user in that group by following. Input Format: The first line contains two integers n (number of users) and m (number of relationships). The next m lines each define a pair of users (u, v) indicating that user u follows user v. Output Format: Print the number of separate groups of users. Example: Input: 5 4 1 2 2 3 3 4 1 5 Output: 2