#include <fstream>
using namespace std;

int main()
{
    ifstream fin ("fractii.in");
    ofstream fout ("fractii.out");
    int a, b, n, i, j, r, z=0;
    fin >> n;
    for (i=1; i<=n; i++)
    {
       for (j=i+1; j<=n; j++)
    {
        a=i;
        b=j;
        while (r=a%b)
        {
            a=b;
            b=r;
        }
        if (b==1){
        z=z+1;}
    }
    }
    fout << z*2+1;
    return 0;
}