#include <fstream>
using namespace std;

ifstream fin("fractii.in");
ofstream fout("fractii.out");

int n, cate;

int euclid(int, int);
int main()
{
    int i,j,f;
    fin>>n;
    //if(n%2==0) f=n/2; else f=n/2+1;
    for(i=1;i<=n;i++)
        for(j=i+1;j<=n;j++)
        if(euclid(i,j)==1) cate=cate+2;

    cate++;
    fout<<cate;
    return 0;

}

int euclid(int a, int b)
{
    int r;
    while(b)
    {
        r=a%b;
        a=b;
        b=r;
    }
    return a;

}