#include <iostream>
#include <fstream>
#include <map>
using namespace std;

int cmmdc(int a, int b) {
    if (b==0) return a;
    return cmmdc(b, a%b);
}

main() {
    ifstream cin("fractii.in");
    ofstream cout("fractii.out");
    int n;
    cin>>n;
    int k = 2*n-1;
    for (int i = 2; i <=n; i++) {
        for (int j = i+1; j <=n; j++) {
            if (cmmdc(i, j) == 1) {
                k+=2;
            }
        }
    }
    cout<<k;
}