#include <iostream>

using namespace std;

int main()
{
    long long n;

   cin >> n;

   if (n <= 2)
    cout << 16;
   else if (n == 3)
    cout << 15;
   else
   {
       if (n % 2 == 0)
       {
           if (n / 2 % 2 == 0)
                cout << 15;
           else
                cout << 16;
       }
       else
       {
           if (n / 2 % 2 == 0)
            cout << 16;
           else
            cout << 15;
       }
   }
}