#include<fstream>
using namespace std;
ifstream f("fractii.in");
ofstream g("fractii.out");
int n, i, k, j, nr;
int prim(int x, int y){
	for (k=2;k<=x;k++)
		if (x%k==0 && y%k==0)
			return 0;
return 1;
}
int main(){
	f>>n;
	for (i=1;i<=n;i++)
		for (j=i+1;j<=n;j++)
		{ if (prim(i,j))
			nr++;
		  }
g<<nr*2+1;
f.close();
g.close();
return 0;
}