#include <iostream>
using namespace std;
int main()
{
    int a, b, c, d, e, num = 0;
    cin >> a;
    for (int i = 100; i <= 999; i++)
    {
        b = i / 100;
        c = i / 10 - b * 10; 
        d = i - b * 100 - c * 10;
        for (int j = 10; j <= 31; j++)
        {
            if (i == j * j)
            {
                if (b == c)
                {
                    num++;
                }
                else if (d == c)
                {
                    num++;
                }
                else if (d == b)
                {
                    num++;
                }
            }
        }
        if (num == a)
        {
            e = i;
            break;
        }
    }
    cout << e;
    return 0;
}