#include<stdio.h>
#include<stdbool.h>
#include<string.h>

bool isPalindrome(int num) {
    if (num < 0) return false;
    int originalNum = num;
    int reversedNum = 0;
    while (num > 0) {
        int digit = num % 10;
        reversedNum = reversedNum * 10 + digit;
        num /= 10;
    }
    return originaNum == reversedNum;
}
int main() {
    int input;
    if (scanf("%d", &input)!= 1) {
        printf("Invalid input\n");
        return 1;
    }
    if (input < -1000 || input > 1000) {
        printf("Invalid input\n");
        return 1;
    }
    if (input < 0) {
        printf("Invalid input\n");
        return 1;
    }
    int currentNum = input + 1;
    while (true) {
        if (isPalindrome(currentNum)) {
            printf("%d\n", currentNum);
            break;
        }
        currentNum++;
    }
    return 0;
}