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;
}
}