#include<stdio.h>
int ispalindrome(int n){
    int original =n,reversed= 0,digits;
    while(n>0){
        digits = n % 10;
        reversed = reversed*10 + digits;
        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;
}