#include <fstream>

using namespace std;

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

int n, p, q = 1, suma = 0, aux, i;
/*int n,i,k,x[100001];
long suma = 1;*/

int main()
{
    fin >> n;

    for(p = 2; p <= n; p++){
        for(i = 2; i <= min(p,q); i++){
            if((p % i == 0) && (q % i == 0)){
                suma++;
                if(p != q){
                    suma++;
                }
                break;
            }
        }
        if(q < n){
            q++;
            p--;
        } else {
            q = p;
        }
    }

    suma = n*n - suma;

   /* for(i=1;i<=n;++i){
       	x[i]=i;
       	fout << x[i] << endl;}
       	fout << endl;
	for(i=1;i<=n;++i)
        for(k=2*i;k<=n;k+=i){
            fout << x[k] << " ";
            x[k]-=x[i];
            fout << x[k] << endl;}
            fout << endl;
	for(i=2;i<=n;++i)
       	suma=suma+2*x[i];*/

    fout << suma;

    return 0;
}