#include<iostream>
#include<fstream>
using namespace std;
int main()
{
    ifstream f("fractii.in");
    ofstream g("fractii.out");

    int phi[1000],i,j,N;
    long s=0;
    f>>N;

for (int i = 1; i <= N; ++i)
    phi[i] = i-1;
for (int i = 2; i <= N; ++i)
    for (int j = 2*i; j <= N; j += i)
        phi[j] -= phi[i];

      for(i=1;i<=N;i++)
        s+=N-phi[i];

        g<<s;

}