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

ifstream f_in("fractii.in");
ofstream f_out("fractii.out");

long long prim(int a, int b)
{
    int r = a%b;
    while (b!=0){r=a%b;a=b;b=r;}
    return a;}

long long Euler(int n){
    long long sum=0;
    for(int i=1;i<n;i++)
        if(prim(n,i)==1)
            sum++;
    return sum;
}

int main(){
    long long n, sum=0;
    f_in>>n;
    for(long long i=2;i<=n;i++)
        sum+=Euler(i);
    f_out<<sum*2+1;

return 0;
}