#include <fstream>

using namespace std;

int main()
{
    ifstream cin("fractii.in");
    ofstream cout("fractii.out");
    int N, P, P_copy, total, n;
    cin >> N;
    n = 0;
    total = ((N-1)*N)/2;
    for ( P = 2; P <= N/2; ++P )
    {
        for ( P_copy = 2; P_copy <= N; P_copy += P_copy )
        {
            ++n;
            ++P;
            P_copy = P;
        }
    }
    total = (total - n)*2+1;
    cout << total;
    return 0;
}