#include <iostream>
#include<fstream>
using namespace std;
ifstream in("fractii.in");
ofstream out("fractii.out");
int main()
{
    int n,i,j,k,ok;
    in>>n;
    in.close();
    k=(2*n)-1;
    for(i=1;i<=n;i++)
        for(j=1;j<=n;j++)
        {
            ok=1;
            if((i%2==0&&j%2==0)||(i%3==0&&j%3==0))ok=0;
            if(ok==1)
            if((i%j!=0)&&(j%i!=0))
            {
                cout<<i<<"/"<<j<<"\n";
                k++;
            }
        }
    out<<k;
    return 0;
}