#include <fstream>
using namespace std;

unsigned short int cmmdc(unsigned short int a, unsigned short int b){
    unsigned short int r;
    while(b){
        r=a%b;
        a=b;
        b=r;
    }
    return a;
}

unsigned short int nr_fractii(unsigned long N){
    unsigned short int i, j, z=0;
    for(i=2; i<=N; i++) for(j=2; j<=N; j++) if(cmmdc(i, j)==1) z++;
    return z;
}

int main()
{
    ifstream fin("fractii.in");
    ofstream fout("fractii.out");
    unsigned long N;
    fin >> N;
    fout << nr_fractii(N)+N*2-1;
    fin.close();
    fout.close();
    return 0;
}