#include<bits/stdc++.h>
using namespace std;
int main()
{
    freopen("fractii.in","r",stdin);
    freopen("fractii.out","w",stdout);
    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;
}