#include <bits/stdc++.h>

using namespace std;
ifstream fin("fractii.in");
ofstream fout("fractii.out");
int nr=1,i,j,n;

int gcd(int a , int b)
{
   if(b==0) return a;
   a%=b;
   return gcd(b,a);
}

int main()
{
    fin>>n;
    for(i=1;i<=n-1;i++){
        for(j=i+1;j<=n;j++){
         if(gcd(i,j)==1) nr+=2;
        }
    }
    fout<<nr;
    return 0;
}