#include <fstream>
using namespace std;
ifstream is ("fractii.in");
ofstream os ("fractii.out");

long n;
int Cmmdc(int a, int b);

int main()
{
    is >> n;
    long cnt = 0;
    for(int i = 1; i <= n; ++i)
        for(int j = i + 1; j <= n; ++j)
        {
            if(Cmmdc (i, j) == 1)
                cnt += 2;
        }
    cnt += 1;
    os << cnt;
    return 0;
}

int Cmmdc(int a, int b)
{
    if(a == 1)
        return a;
    if(b == 1)
        return b;
    while(a != b)
    {
        if (a > b)
            a -= b;
        if (b > a)
            b -= a;
    }
    return a;

}