#include <iostream>
#include <fstream>
#include <cmath>
using namespace std;

int main()
{
    ifstream fin("fractii.in");
    ofstream fout("fractii.out");
    int n,i,j,k,s=1,b=0;
    fin>>n;
    for(i=2;i<=n;i++)
    {
        for(j=2;j<=n;j++)
        {
            s=1;
            for(k=2;k<=j;k++)
            {
                if(i%k==0 && j%k==0)
                {
                    s=0;
                }
            }
            if(s==1)
            {
                b++;
            }
        }
    }
    fout<<b+2*n-1;

    fin.close();
    fout.close();
    return 0;
}