#include <stdio.h>

int isPalindrome(int x) {
    int original = x;
    int rev = 0;
    
    while (x > 0) {
        rev = rev * 10 + (x % 10);
        x /= 10;
    }
    
    return (rev == original);
}

int main(void) {
    int n;
    if (scanf("%d", &n) != 1) {
        pritnf("Invalid input");
        return 0;
    }
    
    if (n < 0 || n < -1000 || n > 1000) {
        printf("Invalid input");
        return 0;
    }
    
    int candidate = n + 1;
    while (1) {
        if (isPalindrome(candidate)) {
            printf("%d", candidate);
            break;
        }
        candidate++;
    }
     return 0;
}