#include <iostream>
#include <cstdlib>
#include <fstream>
using namespace std;

ifstream fin("fractii.in");
ofstream fout("fractii.out");
 
int gcd(int u, int v) {
    while ( v != 0) {
        int r = u % v;
        u = v;
        v = r;
    }
    return u;
}
 
int f(int n){
   int s = 0;
   for(int i=1;i<=n;i++)
   if(gcd(i,n)==1)
   s+=2;
   return s;
}
 
int main()
{
    int N=-1, n;
    fin >> n;
    for(int i=1; i<=n;i++)
    N+=f(i);
    fout << N;
}