import java.util.Scanner; import java.util.HashSet; import java.util.Scanner; import java.util.Set; // 注意类名必须为 Main, 不要有任何 package xxx 信息 public class Main { public static void main(String[] args) { Scanner scanner=new Scanner(System.in); int n= scanner.nextInt(); System.out.println(getUniqueDigits(n)); } public static int getUniqueDigits(int n){ Set<Integer> seen=new HashSet<>(); int result=0; while(n>0){ int digit=n%10; if(!seen.contains(digit)){ seen.add(digit); result =result*10+digit; } n/=10; } return result; } }