#include <iostream>
#include <fstream>

using namespace std;

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

int N;


void cit(){
    in>>N;
}
int cmmdc(int a, int b)
{
    if((!a) || (!b)) return a+b;
    if(a>b) return cmmdc(a%b,b);
    return cmmdc(a,b%a);
}
int red(int N,int nr){
    int counter = 0;
    for(int i = 1; i <= N; i ++){
        if(cmmdc(nr,i) == 1){
            counter++;
        }
    }
    return counter;
}
int F(int k){
    if(k == 1){
        return N;
    }else{
        return F(k-1) + red(N,k);

    }
}

int main()
{   cit();
    out<<F(N);


    return 0;
}