#include <iostream>
#include<bits/stdc++.h>
using namespace std;
 
void qsortfirst(pair<int,int> p[],int low,int up){
 
	if(low>=up)
		return;
	pair<int,int> temp;
	int i=low+1,j=up,pivot=p[i].first;
	while(i<=j){
		while(p[i].first<pivot)
			i++;
		while(p[j].first>pivot)
			j--;
		if(i<j){
			temp=p[i];
			p[j]=p[i];
			p[i]=temp;
			j--;
			i++;
		}
		else if(i==j)
			i++;
	}
	temp=p[j];
	p[j]=p[low];
	p[low]=temp;
	qsortfirst(p,low,j-1);
	qsortfirst(p,j+1,up);
}
 
int main() {
	// your code goes here
	pair<int,int> p[5];
	for(int i=0;i<5;i++)
		cin>>p[i].first>>p[i].second;
	qsortfirst(p,0,5);
	for(int i=0;i<5;i++)
		cout<<p[i].first<<" "<<p[i].second;
	return 0;
}
 

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