#include <fstream>
#include <iostream>

using namespace std;

int main()
{
    int n,p,q,k;
    ifstream fin("fractii.in");
    fin>>n;
    k=1;
    fin.close();
    ofstream fout("fractii.out");
    for(p=1;p<=n;p++)
            for(q=1;q<=n;q++)
              if(p%2==1 || q%2==1)
              {

               if(p<q)
                {
                    if(p/q==0 && p%q==p)
                  {
                    k++;
                    fout<<p<<"/"<<q<<" ";
                  }
                }
              else
               if(p>q)
                {
                    if(p%q<=p-q)
                  {
                    k++;
                    fout<<p<<"/"<<q<<" ";
                  }
                }
            }

     fout<<"\n";
    fout<<k;
    fout.close();
    return 0;
}