package com.company;
import java.sql.Array;
import java.util.*;
import java.lang.String;
public class Main {

    public static void main(String args[]) {
        Stack dates = getPalindromicDate(2021);
        System.out.println(dates);
    }
        public static Stack getPalindromicDate(int year){
            Stack<String> stack = new Stack<String>();
            int month = getMonth(year);
            int day = getDay(year);
            if (!checkDate(day, month)) return stack;
            String monthString = getMonthString(year);
            String dayString = getDayString(year);
            stack.push(monthString);
            stack.push(dayString);
            stack.push(Integer.toString(year));
            return stack;
        }
        public static int reverseDate ( int n){
            String number = Integer.toString(n);
            String output;
            output = "";
            for (int i = number.length() - 1; i >= 0; i--)
                output += number.charAt(i);
            return Integer.parseInt(output);
        }
        public static boolean checkDate ( int day, int month){
            int[] days = {31, 28, 31, 30, 31, 30, 31, 31, 30, 31, 30, 31};
            if (month > 12) return false;
            if (days[month - 1] < day) return false;
            return true;
        }
        public static int getMonth ( int reverseYear){
            String number = Integer.toString(reverseYear);
            String output = "";
            output += number.charAt(3);
            output += number.charAt(2);
            return Integer.parseInt(output);
        }

        public static String getMonthString ( int reverseYear){
            String number = Integer.toString(reverseYear);
            String output = "";
            output += number.charAt(3);
            output += number.charAt(2);
            return output;
        }
        public static int getDay ( int reverseYear){
            String number = Integer.toString(reverseYear);
            String output = "";
            output += number.charAt(1);
            output += number.charAt(0);
            return Integer.parseInt(output);
        }
        public static String getDayString ( int reverseYear){
            String number = Integer.toString(reverseYear);
            String output = "";
            output += number.charAt(1);
            output += number.charAt(0);
            return output;
        }
    }