#include<stdio.h>
int ispalindrome(int n){
    int original = n,reversed = 0,digit;
    while(n>0){
        digit = n % 10;
        reversed = reversed*10 + digit;
        n/=10;
    }
    return original == reversed;
}
int main(){
    int n;
    if(scanf("%d",&n) != 1){
        printf("Invalid input");
        return 0;
    }
    if(n<0 || n> 1000){
        printf("Invalid input");
        return 0;
    }
    int next = n + 1;
    while (!ispalindrome(next)){
        next++;
    }
    printf("%d", next));
    return 0;
}