#include <iostream>
#include <fstream>
using namespace std;
int main(){
    ifstream f("fractii.in");
    int n; f>> n;
    int fractii = 0;
    for(int i = 1; i <= n; i++){
        for(int j = 1; j <= n;j++){
                if(i == 2*j) continue;
                if(j==1){
                    cout << i << "/" << j << endl;fractii++;continue;
                }
            if(i == j && i == 1) {
                    cout << i << "/" << j << endl;fractii++;continue;
                }

            if(i % j != 0) {cout << i << "/" << j << endl;fractii++;continue;}

        }
    }
    cout << fractii;
    ofstream g("fractii.out");
    g << fractii;
}