#include <iostream>
#include <fstream>
#include <cmath>

using namespace std;

long cmmdc(long a,long b)
{
    long x;
    while(a!=b)
    {
        x=abs(a-b);
        b=a;
        a=x;
    }
    return a;
}

int main()
{
    long n,i,j,nr=1;
    ifstream f("fractii.in");
    ofstream g("fractii.out");
    f>>n;
    for(i=1;i<=n;i++)
        for(j=i+1;j<=n;j++)
                if(cmmdc(i,j)==1) nr+=2;
    g<<nr;
    f.close();
    g.close();
    return 0;
}