#include <fstream>
using namespace std;
int cmmdc(int x, int y)
{
    int z;
    while (y)
        {
        z=x%y;
        x=y;
        y=z;
    }
    return x;
}

int nr_prime(int x,int n)
{
    int k, cnt=1;
    for(k=2;k<=n; k++)
        if(cmmdc(x,k)==1) cnt++;
    return cnt;
}

int main()
{
    ifstream in("fractii.in");
    ofstream out("fractii.out");
    int n,cnt,i;
    in>>n;
   cnt=n;
   for(i=2; i<=n;i++)
   {
    cnt=cnt+nr_prime(i,n);
   }
   out<<cnt<<'\n';
        return 0;
}