#include <iostream>
using namespace std;
bool isHuiWen(int n)
{
    int sum = 0;
    int m = n;
    while (n !=0)
    {
        sum = sum * 10 + n%10;
        n = n /10;
    }
    return sum == m;
}
int main()
{
    int X;
    cin>>X;
    int n = X+1;
    while(isHuiWen(n) == false) n++;
    cout<<n<<endl;
}
/**************************************************************
	Problem: 2094
	User: wangyiyang
	Language: C++
	Result: Accepted
	Time:33 ms
	Memory:2072 kb
****************************************************************/