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

int * ciur(int n)
{
    int nr=0;
    queue <int> q;
    int *vect=new int [n+1];
    for(int i=1;i<=n;++i)
    vect[i]=i-1;

    vect[0]=1;

    for(int i=2;i<=n;++i)
    for(int j=i+i;j<=n;j+=i)
    vect[j]=vect[j]-vect[i];
    return vect;
}

int indicator(int x,int *ciur)
{
    long long int nr=x;
    long long int nr_1=1;
    for(int i=1;i<=ciur[0]&&ciur[i]<=x;++i)
    if(x%ciur[i]==0)
    {
        nr=nr/ciur[i];
        nr_1=nr_1*(ciur[i]-1);
    }
    nr=nr*nr_1;
    return nr;
}

int main()
{
    int n;
    f>>n;
    int *v_ciur=ciur(n);

    //for(int i=1;i<=n;++i)
    //g<<v_ciur[i]<<" ";
    long long int suma=0;
    for(int i=1;i<=n;++i)
    suma+=2*v_ciur[i];
    g<<suma+1;

    return 0;
}