#include<fstream>
using namespace std;

ifstream f("fractii.in");
ofstream g("fractii.out");

bool sht(int a, int b)
{
    while(b)
    {
        int r=a%b;
         a=b;
         b=r;
    }
    if(a==1)
        return true;

}

int N, n, s, i;

int main()
{
    f>>N;
    f.close();
    while(n - 1!= N)
    {
        for(i = 1; i<= N; i++)
            if(sht(n, i))
                s++;
        n++;
    }

    g<<s-1;
    g.close();
    return 0;
}