import java.lang.reflect.Array;
import java.util.*;

public class Main{
    static void sd(String ss) {

        StringBuilder stl=new StringBuilder();
        StringBuilder ad=new StringBuilder();

        stl.append(ss);
        ad=stl.reverse();
        boolean e=ss.contentEquals(ad);
        if(e) {
            System.out.println(ad);
            break;
        }

    }

        public static void main(String[] args) {
        Scanner scan=new Scanner(System.in);
        int n=scan.nextInt();
        int year=n/10000;
        int mounth=(n/100)%100;
        int day=n%100;





        for(int i=0;i<100;i++) {

            for(int j=mounth;j<13;j++) {

                if(j==1||j==3||j==5||j==7||j==8||j==10||j==12) {

                    for(int u=day;u<=31;u++) {
                        if(j<10) {
                            if(u<10) {
                                String s=""+year+"0"+j+"0"+u;
                                sd(s);


                            }
                            else {
                                String s=""+year+"0"+j+u;
                                sd(s);

                            }
                        }
                        else {
                            if(u<10) {
                                String s=""+year+j+"0"+u;
                                sd(s);

                            }
                            else {
                                String s=""+year+j+u;
                                sd(s);

                            }
                        }
                    }

                    day=1;
                }


                else if(j==2&&(year%4==0&&year%100!=0||year%400==0)) {
                    for(int u=day;u<30;u++) {
                        if(u<10) {
                            String s=""+year+"0"+j+"0"+u;
                            sd(s);

                        }
                        else {
                            String s=""+year+"0"+j+u;
                            sd(s);

                        }

                    }
                    day=1;
                }



                else if(j==2){
                    for(int u=day;u<29;u++) {
                        if(u<10) {
                            String s=""+year+"0"+j+"0"+u;
                            sd(s);

                        }
                        else {
                            String s=""+year+"0"+j+u;
                            sd(s);
                        }
                    }
                    day=1;
                }


                else {
                    for(int u=day;u<31;u++) {
                        if(j<10) {
                            if(u<10) {
                                String s=""+year+"0"+j+"0"+u;
                                sd(s);

                            }
                            else {
                                String s=""+year+"0"+j+u;
                                sd(s);

                            }
                        }
                        else {
                            if(u<10) {
                                String s=""+year+j+"0"+u;
                                sd(s);

                            }
                            else {
                                String s=""+year+j+u;
                                sd(s);

                            }
                        }
                    }
                    day=1;

                }

            }
            mounth=1;

            year+=1;
        }


        scan.close();

           
                    

        }
}