#include <fstream>
using namespace std;

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

int cmmdc(int a, int b) {
    if(!b)
        return a;
    return cmmdc(b, a % b);
}

int main() {
    int n, s = 0;
    fin >> n;
    for(int i = 2; i <= n; ++i)
        for(int j = i+1; j <= n; ++j)
            if(cmmdc(i, j) == 1)
                s += 2;
    fout << s + 2*n - 1;
}