/*

     PROB:frac1

     ID:wanghan

     LANG:C++

 */

 #include "iostream"

 #include "cstdio"

 #include "cstring"

 #include "string"

 #include "algorithm"

 #include "vector"

 using namespace std;

 int n;

 int gcd(int a,int b){

     if(b==)  return a;

     return gcd(b,a%b);

 }

 struct Node{

     int x,y;

     double ans;

 };

 vector<Node> p;

 bool cmp(Node a,Node b){

     return a.ans<b.ans;

 }

 int main()

 {

     freopen("frac1.in","r",stdin);

     freopen("frac1.out","w",stdout);

     cin>>n;

     for(int i=;i<=n;i++){

         for(int j=min(n,i+);j<=n;j++){

             int x,y;

             x=i/gcd(i,j),y=j/gcd(i,j);

             Node t;

             t.x=x,t.y=y,t.ans=(double)x/(double)y;

             p.push_back(t);

         }

     }

     sort(p.begin(),p.end(),cmp);

     cout<<p[].x<<"/"<<p[].y<<endl;

     for(int i=;i<p.size();i++){

         if(p[i].x==p[i-].x&&(p[i].y==p[i-].y)) continue;

         cout<<p[i].x<<"/"<<p[i].y<<endl;

     }

     return ;

 }