#include<bits/stdc++.h> using namespace std; int f(int k){ if(k==4){ cout<<"4,5-->9,10\n8,9-->4,5\n2,3-->8,9\n7,8-->2,3\n1,2-->7,8"<<endl; } else{ cout<<k<<","<<k+1<<"-->"<<2*k+1<<","<<2*k+2<<endl; cout<<2*k-1<<","<<2*k<<"-->"<<k<<","<<k+1<<endl; f(k-1); } } int main(){ int n; cin>>n; f(n); return 0; }