#include <iostream>
#include <fstream>
using namespace std;
ifstream fin("fractii.in");
ofstream fout("fractii.out");
int main()
{
    long long n,i,j,s=0;
    cin>>n;
    s = 2*n-1;
    for(i=2;i<=n;i++)
        for(j=2;j<=n;j++)
        {
            if(i%j==0 || j%i==0)
                int cod = 1;
            else s++;
        }
    cout<<s;
    return 0;
}