#include <stdio.h>

int isPalindrome(int num) {
    int rev = 0, temp = num;
    while(temp>0) {
        rev=rev*10+(temp%10);
        temp /= 10;
    }
    return rev == num;
}
int main() {
    int num;
    if(scanf("%d",&num)!=1||num < 0) {
        printf("Invalid input\n");
        return 0;
    }
    num++; 
    while (!isPalindrome(num)) {
        num++;
    }
    printf("%d\n", num);
}