#include <iostream>
using namespace std;
unsigned long long n;
int a[110];
int main()
{
    cin>>n;
    for (unsigned long long i=n+1;;i++)
    {
        unsigned long long x=i,j=1,l=0;
        bool f=1;
        while (x)
            x/=10,l++;
        x=i;
        while (x)
            a[j]=x%10,x/=10,j++;
        for (int k=1;k<=l;k++)
            if (a[k]!=a[l-k+1]) 
                f=0;
        if (f)
        {
            cout<<i;
            break;
        }
    }
    return 0;
}