#include <iostream>
using namespace std;

int main()
{
    cin>>n;
    if(n<=2)
        cout<<16;
    else
    {
        if(n==3)
            cout<<15;
        else
        {
            if(n/2%2==0)
            {
                cout<<15;
            }
            else
            {
                if(n/2%2==1)
                {
                    cout<<16;
                }
            }
        }
    }
    return 0;
}