#include <iostream>
#include <fstream>
int b[20],st,s,maxim=1,i,n,nr;
using namespace std;

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

            }
            if(a == 1) nr++;
        }
    }
    fout << nr*2+1;

}