#include<fstream>
using namespace std;
ifstream fin("fractii.in");
ofstream fout("fractii.out");

double long n, i, j, k=0;
int cmmdc(int x,int y){
    if(x>y)
        return cmmdc(x-y,y);
    if(y>x)
        return cmmdc(x,y-x);
    if(x==y)
        return x;
}
int main(){
	fin >> n;
	for(i=1;i<=n;i++)
        for(j=i;j<=n;j++)
            if(cmmdc(i,j)==1)
                if(i==j)
                    k++;
                else
                    k+=2;
	fout<<k;
	return 0;
}