#include <iostream>
#include <fstream>

using namespace std;

int main()
{
    ifstream x("fractii.in");
    ofstream y("fractii.out");

    int n,p,q,nr;

    nr=0;
    x>>n;

    p=1;


    while (p<=n)
        {   q=1;
            while (q<=n)
              {if ((p%q!=0 or q==1)and (q%p!=0 or p==1)) {nr++; y<<p<<'/'<<q<<' ';}

            q++;}
        p++;}


    y<<nr;

    x.close();
    y.close();

    return 0;

}