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