#include <bits/stdc++.h>
#include "minerals.h"
using namespace std;
typedef long long ll;
#define st first
#define nd second
#define pb push_back
const int maxn = 1e5+7;
/*
int para[] = {0,1,3,3,1,2,4,4,2};
set<int> zbior;
int Query(int x){
if(zbior.count(x)){
zbior.erase(x);
}
else{
zbior.insert(x);
}
set<int> aktualny;
for(auto i : zbior){
aktualny.insert(para[(i)]);
}
return aktualny.size();
}
void Answer(int a, int b) {
cout<<a<<" "<<b<<"\n";
}
*/
bool zaznaczone[maxn];
vector<pair<int,int>> wyniki;
double fi = 1.61;
mt19937 gen(234678);
void rek(vector<int> num1,vector<int> num2,bool parzystosc,bool obrot){
shuffle(num1.begin(),num1.end(),gen);
shuffle(num2.begin(),num2.end(),gen);
if(num1.size() == 1){
//cout<<num1.size()<<" "<<num2.size()<<" "<<parzystosc<<"\n";
wyniki.pb({num1[0],num2[0]});
return;
}
vector<int> x1,x2,y1,y2;
int dlu = num1.size(),nowy,stary;
int a = (double(dlu)/fi), b = dlu-a;
if(parzystosc == 0){
for(int i=0;i<b;i++){
stary = Query(num1[i]);
x1.pb(num1[i]);
}
for(int i=b;i<dlu;i++){
y1.pb(num1[i]);
}
}
else{
for(int i=0;i<a;i++){
x1.pb(num1[i]);
}
for(int i=a;i<dlu;i++){
stary = Query(num1[i]);
y1.pb(num1[i]);
}
}
for(int i=0;i<dlu;i++){
if(x2.size() == x1.size()){
y2.pb(num2[i]);
continue;
}
if(y2.size() == y1.size()){
x2.pb(num2[i]);
continue;
}
nowy = Query(num2[i]);
if(obrot){
if(nowy == stary){
y2.pb(num2[i]);
}
else{
x2.pb(num2[i]);
}
}
else{
if(nowy == stary){
x2.pb(num2[i]);
}
else{
y2.pb(num2[i]);
}
}
stary = nowy;
}
rek(x1,x2,0,!obrot);
rek(y1,y2,1,!obrot);
return;
}
void Solve(int n) { //Query(x) // Answer(a,b)
vector<int> vect1,vect2;
int a=0,b;
for(int i=1;i<=2*n;i++){
b = Query(i);
if(b != a)
vect1.pb(i);
else
vect2.pb(i);
a = b;
}
rek(vect1,vect2,0,1);
for(int i=0;i<n;i++){
Answer(wyniki[i].st,wyniki[i].nd);
}
}
/*
int main(){
Solve(4);
return 0;
}
*/
