#include <fstream>

using namespace std;

ifstream f("fractii.in");
ofstream g("fractii.out");

int cmmdc(int x, int y)
{
int r;
r = x % y;
while (r != 0)
        {
        x = y;
        y = r;
        r = x % y;
        }
return y;

}
int main()
{
int a,i,nr=0,j;
f>>a;
for (i=2;i<=a-1;i++)
	for (j=i+1;j<=a;j++)
		{
		if (cmmdc(i,j)==1) nr++;
		}
g<<(a-1+nr)*2+1;
f.close();
g.close();
return 0;
}