import java.util.*;
public class Col {
  public static void main(String args[]) {
    Collection<String> c = new LinkedList<String>();
    for (String s : args) {
      c.add(s);
    }
    // First way:
    Iterator<String> i = c.iterator();
    while (i.hasNext()) {
      String s = i.next();
      if (s.equals("a")) {
        i.remove();
      }
      System.out.println(s);
    }
    System.out.println("tracinho 1");
    Collection<String> noDup = new HashSet<String>(c);
    for (String s : noDup) {
      System.out.println(s);
    }
    System.out.println("tracinho 2");
    // Second way:
    for (String s : c) {
      System.out.println(s);
    }
  }
}