#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;
    return 0;
}
/**************************************************************
	Problem: 2094
	User: admin
	Language: C++
	Result: Accepted
	Time:30 ms
	Memory:2072 kb
****************************************************************/