#include <iostream>
#include <fstream>

using namespace std;

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

bool cmmdc(int a,int b){
    int r;
    while(b){
        r=a%b;
        a=b;
        b=r;
    }
    if(a==1)
        return true;
    else
        return false;
}

int  ciur(int k, int n){
    int c=0;
    for(int j=1;j<=n;j++){
        if(cmmdc(j,k))
            c++;
    }
    return c;
}


int main()
{
   int n;
   f>>n;
   int s=n;
   for(int i=2;i<=n;i++){
    s+=ciur(i, n);
   }
   g<<s;
}