#include <fstream>
using namespace std;
ifstream f("data.in");
ofstream g("data.out");
bool verifprop(int p, int q)
{
    if((p == 1 && q == 1)||p % q != 0 || q == 1)
        return 1;
    return 0;
}
int main()
{
    int n,p,q,cate = 0;
    f>>n;
    f.close();
    p = 1;
    while(p <= n)
    {
        for(q = 1; q <= n; q++)
            if(verifprop(p,q))
                g << p << '/' << q << ' ' << endl,cate++;
        p++;
    }
    g << cate << endl;
    g.close();
}