#include <fstream>
using namespace std;

ifstream fin("fractii.in");
ofstream fout("fractii.out");

int cmmdc(int a, int b)
{
    while(a&&b)
    {
        if(a>b)
            a=a%b;
        else
            b=b%a;
    }
    return(a+b);
}

int main()
{
    int n,i,j,s=0;
    fin>>n;
    for(i=1;i<=n;++i)
        for(j=1;j<i;++j)
            if(cmmdc(i,j)==1)
                s++;
    fout<<s*2+1;
}