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