Distributed Request Tracker

In a distributed system, multiple servers process requests. Each log entry consists of a ServerID and a RequestID. Your task is to find the RequestID that was processed by the highest number of *distinct* servers. If multiple requests have the same maximum count of distinct servers, return the one that is lexicographically smallest. Input Format: The first line contains an integer N, the number of log entries. The next N lines each contain two strings: ServerID and RequestID. Output Format: A single string representing the RequestID with the most unique servers. Example: Input: 4 S1 R100 S2 R100 S1 R200 S3 R100 Output: R100 (Explanation: R100 is on S1, S2, S3 [3 servers]. R200 is only on S1 [1 server].)