// editor3
#include <stdio.h>
int ispalindrome(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("Invalid input");
            return 0;
        }
        input =(int)tempInput;
        if(tempInput !=input || input <0)
        {
            printf("Invaliud input");
            return 0;
        }
        int next=input+1;
        while(!ispalindrome(next))
        {
            next++;
        }
        printf("%d", next);
        return 0;
    }