#include <fstream>

using namespace std;
ifstream f("fractii.in");
ofstream g("fractii.out");
long r,n,s,i,j;
int cmmdc (long a ,long  b )
{
    r=a%b;
    while(r>0)
    {
        a=b;b=r;r=a%b;
    }
    return b;
}
int main()
{f>>n;
s=0;
for(i=1;i<=n;i++)
{
    for(j=i+1;j<=n;j++)
    {
        if(cmmdc(i,j)==1)s++;
    }
}
g<<s*2+1;
f.close();
g.close();
    return 0;
}