import java.util.*;

public class Main {

public static class Solution {

public String nearestPalindromic(String n) {

long val = Long.parseLong(n);

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

long k1 = val - i, k2 = val + i;

if (isPalindrome(k1)) {

return String.valueOf(k1);

}

if (isPalindrome(k2)) {

return String.valueOf(k2);

}

}

}

private boolean isPalindrome(long k) {

long x = k, rev = 0;

for ( ; k > 0; ) {

rev = rev * 10 + k % 10;

k /= 10;

}

return rev == x;

}

}

public static void main(String[] args) {

Solution solution = new Solution();

String s = solution.nearestPalindromic("807045053224792883");

System.out.println(s);

}

}