#include <bits/stdc++.h>

using namespace std;

ifstream fin("fractii.in");
ofstream fout("fractii.out");

using ull = unsigned long long;

int n;
ull sum, a[1000005];

int main() {
    fin >> n;
    a[1] = 1;
    for (int i = 2; i <= n; i++) {
        a[i] = i - 1;
    }

    for (int i = 2; i <= n; i++) {
        sum += a[i];
        for (int j = i * 2; j <= n; j++) {
            a[j] -= a[i];
        }
    }

    fout << sum * 2 + 1;
}