import java.util.ArrayList;

import java.util.List;

import java.util.concurrent.atomic.AtomicInteger;

class LogStream {

private List<String> logs; // Store log messages

private int maxLogs; // Maximum number of logs to store

private AtomicInteger logCounter = new AtomicInteger(0); // Atomic counter for unique log IDs

public LogStream(int maxLogs) {

this.logs = new ArrayList<>();

this.maxLogs = maxLogs;

}

public synchronized void log(String message) { // Synchronized for thread safety

logCounter.incrementAndGet();

String logId = "log-" + logCounter.get(); // Generate a unique ID

logs.add(logId + ": " + message); // Add log message with ID

if (logs.size() > maxLogs) {

logs.remove(0); // Remove the oldest log message if limit is reached

}

}

public List<String> getLogs() {

return new ArrayList<>(logs); // Return a copy to prevent external modification

}

public static void main(String[] args) {

// Example usage

LogStream logStream = new LogStream(5); // Limit to 5 logs

logStream.log("This is log message 1.");

logStream.log("This is log message 2.");

logStream.log("This is log message 3.");

logStream.log("This is log message 4.");

logStream.log("This is log message 5.");

logStream.log("This is log message 6."); // Will replace the oldest log

System.out.println(logStream.getLogs());

}

}