package test1;
import java.util.*;
public class Main
{
    public static void main(String[] args)throws Exception
    {
        Scanner sc = new Scanner(System.in);
        String str = sc.nextLine();
        int[] num = new int[10];
        for(int i = 0;i<str.length();i++)
        {
            num[str.charAt(i)-'0']++;
        }
        num[0]++;
        int j = findMin(num);
        if( j == 0) {
            System.out.print(1);
            int count = num[j] - 1;
                while(count-- >= 0)
                    System.out.print(0);
            return;
        }else{
            int count = num[j];
            while(count-- >= 0)
                System.out.print(j);
            return;
        }
    }
    static int findMin(int[] a) {
        int num = a[0];
        int j = 0;
        for(int i = 1; i < 10; ++i) {
            if(num > a[i]) {
                num = a[i];
                j = i;
            }
        }
        return j;
    }
}