#include <iostream>
#include <vector>
#include <algorithm>
using namespace std;

class point{
    float a, b;
public:
    point(float a, float b){
        this->a=a;
        this->b=b;
    }

    float getA()
    {
        return a;
    }
    float getB()
    {
        return b;
    }
};

bool sortujPoX(point p1, point p2){
    return (p1.getA() < p2.getA());
}

bool sortujPoY(point p1, point p2){
    return (p1.getB() < p2.getB());
}



int main()
{
   vector<point> v;
   v.push_back(point(4,-1));
   v.push_back(point(-5,1));
   v.push_back(point(0,0));

   for(vector<point>::iterator it=v.begin(); it!=v.end(); it++){
       cout<< ' '<<(*it).getA()<<" "<< (*it).getB();
       cout<<endl<<endl;
   }
cout<<endl<<endl;
   sort(v.begin(), v.end(), sortujPoX);
    for(vector<point>::iterator it=v.begin(); it!=v.end(); it++){
        cout<< ' '<<(*it).getA()<<" "<< (*it).getB();
        cout<<endl<<endl;
    }
cout<<endl<<endl;
    sort(v.begin(), v.end(), sortujPoY);
     for(vector<point>::iterator it=v.begin(); it!=v.end(); it++){
         cout<< ' '<<(*it).getA()<<" "<< (*it).getB();
         cout<<endl<<endl;
     }

    return 0;
}