01. Unique Usernames

package Uprajnenie;

import java.util.LinkedHashSet;
import java.util.Scanner;
import java.util.Set;

public class UniqueUsernames {
    public static void main(String[] args) {
        Scanner scanner = new Scanner(System.in);


        // Read the number of usernames as a string and convert to integer
        int n = Integer.parseInt(scanner.nextLine().trim());

        Set<String> uniqueUsernames = new LinkedHashSet<>();

        // Read usernames and add them to the set
        for (int i = 0; i < n; i++) {
            String username = scanner.nextLine().trim();
            uniqueUsernames.add(username);
        }

        // Print the unique usernames in the order of insertion
        for (String username : uniqueUsernames) {
            System.out.println(username);
        }

        scanner.close();
    }
}