#include <iostream>
using namespace std;
int main()
{
    int n, x = 0;
    cin >> n;
    for (int i = 10;i <= 31;i++)
    {
        int a, b, c;
        a = i*i/100;
        b = i*i/10%10;
        c = i*i%10;
        if (a == b || a == c || b == c)
        {
            ++x;
        }
        if (n == x)
        {
            cout << i*i << endl;
            break;
        }
    }
    return 0;
}