import java.io.*;
import java.util.*;
public class PA {
    static ArrayList<Integer> data = new ArrayList<Integer>();
    public static void main(String[] args) throws FileNotFoundException {
        Scanner io = new Scanner(new File("test.txt"));
        while(io.hasNextInt())
            {
            int ss = io.nextInt();
            if(ss !=-1)
            data.add(ss);
            }

        for(int i=0;i<data.size();i++)
        {
            if(check(data.get(i).toString()))
                System.out.println(data.get(i));
        }
    }
    static boolean check(String p){
        StringBuffer d = new StringBuffer(p);
        if(d.toString().equals("4200"))
        {
          int x =3;
          x++;
        }
        // 1. case
        if(d.length()==1) return true;
        // 2.case
        if(d.length()>=2)
        {
            char ps = d.charAt(0);
            for(int i=1;i<d.length();i++)
            {
                if(ps!=d.charAt(i))
                {
                    break;
                }
                else if(ps==d.charAt(i)&&i==(d.length()-1))
                {
                    return true;
                }
            }
        }
        // 3.case

        if(d.length()>=3)
        {
            if((d.charAt(0)-d.charAt(1))<0)
            {
                for(int i=1;i<d.length();i++)
                {
                    if(d.charAt(i)-d.charAt(i-1)!=1)
                    {
                        break;
                    }
                    else if((d.charAt(i)-d.charAt(i-1)==1)&&(i==d.length()-1))
                        return true;
                }
            }else{
                for(int i=1;i<d.length();i++)
                {
                    //int ct = d.charAt(i)-d.charAt(i-1);
                    if( d.charAt(i)-d.charAt(i-1) !=-1)
                        break;
                    else if((d.charAt(i)-d.charAt(i-1)==-1)&&(i==d.length()-1))
                        return true;
                }
            }
        }
        //4. case
        String cy = d.toString();
        String cx = d.reverse().toString();

        if(cx.equals(cy))
            return true;
        //5. case

        int number = Integer.parseInt(p);
        if(number%100==0)
            return true;
        if(d.length()==4)
        {
            int p1 = Integer.parseInt(d.substring(0,2));
            int p2 = Integer.parseInt(d.substring(2));
            if(p1==p2)
                return true;
        }
        return false;
    }
}