#include <iostream>
using namespace std;
int n;

int main()
{
    cin >> n;
    if(n % 4 == 0)
    {
        cout << "15\n";
        return 0;
    }
    if(n % 4 == 1)
    {
        cout << (15 + n) << "\n";
        return 0;
    }
    if(n % 4 == 2)
    {
        cout << "16\n";
        return 0;
    }
    if(n % 4 == 3)
    {
        cout << (12 + n) << "\n";
        return 0;
    }
    return 0;
}