#include <bits/stdc++.h>
#include <fstream>
using namespace std;
ifstream fin("fractii.in");
ofstream fout("fractii.out");
int gcd(int a,int b) {
    int r;
    r=a%b;
    if(r==0) return b;
    while(r){
        a=b;
        b=r;
        r=a%b;
    }
    return b;
}
int main()
{
    int n,nr=1;
    fin>>n;
    for(int p=2;p<=n;p++){
        for(int q=1;q<=p;q++){
            if(gcd(p,q)==1) nr+=2;
        }
    }
    fout<<nr;
    return 0;
}