#include <iostream>
#include <fstream>

using namespace std;

long long n, i, j, rez, a, b, r;

int main () {
    
    ifstream fin("fractii.in");
    ofstream fout("fractii.out");
    
    fin >> n;
    for (i = 2; i <= n; i++)
        for (j = 1; j < i; j++)
        {
            a = i;  b = j;
            r = a % b;
            while (r != 0)
            {   a = b;  b = r;  r = a % b;  }
            
            if (b == 1)     rez++;
        }
    
    fout << rez*2+1 << "\n";
}