#include<deque>
#include<iostream>
#include<algorithm>
#include<iterator>


using namespace std;

template <typename T>
struct K{
    T bogdan;
    T zygmunt;
    K(T a,T b):bogdan(a),zygmunt(b){}
    friend ostream& operator << (ostream & o,K<T> k){
        o<<k.bogdan<<' '<<k.zygmunt<<'\n';
        return o;
    }
};

int main(){
    deque< K<int> > pol;
    int j=10;
    for(int i=0;i<5;++i,--j){
        pol.push_front(K<int>(i,j));
        pol.push_back(K<int>(j,i));
    }
    deque< K<int> >::iterator iter=pol.begin();
    copy(pol.begin(),pol.end(),ostream_iterator< K<int> >(cout," ;"));

}