import java.util.LinkedHashSet; import java.util.Scanner; import java.util.Set; public class e3 { public static void main(String[] args) {

        Scanner scanner = new Scanner(System.in); while (scanner.hasNext()) {
            String str = scanner.nextLine();
            Set<Character> set = new LinkedHashSet<>(); for (int i = 0; i < str.length(); i++) {
                Character c = str.charAt(i);
                { if (!set.contains(c)) {
                        System.out.print(c);
                        set.add(c);
                    }
                }
            }
            System.out.println();
        }
    }
}