*/
public class Test05 {
public static void main(String[] args) {
Scanner sc = new Scanner(System.in);
String s = sc.next();
char[] arr = s.toCharArray();
LinkedHashSet<String> set = new LinkedHashSet<>();
for (int i = 0; i < arr.length; i++) {
set.add(arr[i]+"");
}
for (String s1 : set) {
System.out.println(s1);
}
//用TreeSet集合也可以实现,但麻烦些
/*TreeSet<String> set = new TreeSet<>(new Comparator<String>() {
@Override
public int compare(String s1, String s2) {
// int num = s1.compareTo(s2);
if (s2.equals(s1)){
return 0;
}
return 1;
}
});
for (int i = 1; i < arr.length; i++) {
set.add(arr[i]+"");
}
System.out.println(set);*/
}
}