#include <iostream>
using namespace std;

int main()
{
    int a;
    int ev = 0, odd = 0;
    cin >> a;
    for(int i = 1; i <= a; i++)
    {
        if(a%2==0)
            ev++;
        else
            odd++;
    }
    cout << ev * odd;
    return 0;
}
