// editor3
#include<stdio.h>
int isPalendrome(int n)
{
    int reversed =0 ,original=n,digits;
    while(n>0)
    {
        digits = n % 10;
        reversed = reversed * 10+digits;
        n/=10;
    }
    return (reversed == original);
}
int main()
{
    float tempInput;
    int input;
    if(scanf("%f",&tempInput)!=1)
   {
       printf("Invaild input");
       return 0;
   }
   input=(int)tempInput;
   if(tempInput != input || input<0)
   {
       printf("Invalid input");
       return 0;
   }
   int next =input +1;
   while(!isPalindrome(next))
   {
       next++;
   }
   printf("%d",next);
   return 0;
}