#include <iostream>
#include <fstream>

using namespace std;

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

int cmmdc(int a,int b)
{
    while(a!=b)
        if(a>b)
        a=a-b;
        else
        b=b-a;
    return a;
}

int main()
{
    int n,i,j,nr=0;
    f>>n;

        for(i=1;i<=n;i++)
        for(j=1;j<=i;j++)
            if(cmmdc(i,j)==1)
                if(i==j)
                    nr++;
                else
                    nr=nr+2;

        g<<nr;

    return 0;
}