Problem Description

During the 2020 Spring Festival, a special date caught everyone’s attention: February 2, 2020. Because if we write this date in the yyyymmdd format as an $8$-digit number, it is 20200202, which happens to be a palindrome. We call such dates palindrome dates.

Some people said that 20200202 is a “once in a thousand years” special day. Xiao Ming does not agree, because less than 2 years later, there is the next palindrome date: 20211202, which is December 2, 2021.

Others said that 20200202 is not only a palindrome date, but also an ABABBABA-type palindrome date. Xiao Ming also does not agree, because after about $100$ years, you can meet the next ABABBABA-type palindrome date: 21211212, which is December 12, 2121. It is not “once in a thousand years”, at most “twice in a thousand years”.

Given an $8$-digit date, please compute what day is the next palindrome date after this date, and what day is the next ABABBABA-type palindrome date after this date.

Input Format

The input contains an eight-digit integer $N$, representing a date.

Output Format

Output two lines, each with one eight-digit number. The first line is the next palindrome date. The second line is the next ABABBABA-type palindrome date.

20200202

20211202
21211212

Hint

For all test cases, $10000101 \le N \le 92200229$, and it is guaranteed that $N$ is an $8$-digit number representing a valid date.

Lanqiao Cup 2020 Second Round Provincial Contest, Group A Problem G (Group B Problem G).

Translated by ChatGPT 5