#include "Memory2_lib.h"
#include<bits/stdc++.h>
using namespace std;

int values[110];

void Solve(int T, int n){
	if(n==1){
		Answer(0,1, 0);
		return;
	}
	int i;
	for(i=0;i<2*n;i++)values[i] = -1;
	int a, b, val;
	a = 0, b = 1, val = Flip(a,b);
	for(i=2;i<2*n;i++){
		int c = Flip(a, i), d =Flip(b, i);
//		printf("%d %d %d %d %d %d\n", a, b, i, val, c, d);
		if(c==d && c==val){
//			printf("gowno\n");
			int e = Flip(b, i+1), f = Flip(i, i+1);
			int j = i+1;
			while(e==f && e!=val){
//				printf("skip\n");
				values[j] = e;
				j++;
				e = Flip(b, j);
				f = Flip(i, j);
			}
			if(e==val && f==val){
//				printf("g1\n");
				values[b] = val;
				values[i] = val;
				a = a;
				b = j;
				val = Flip(a, b);
				i=j;
				continue;
			}
			if(e==val){
		//		printf("g2\n");
				values[a] = val;
				values[b] = val;
				a = i;
				b = j;
				val = f;
				i=j;
				continue;
			}
			if(f==val){
	//			printf("g3\n");
				values[a] = val;
				values[i] = val;
				a = b;
				b = j;
				val = e;
				i=j;
				continue;
			}
			continue;
		}
		if(c==d){
			values[i] = c;
			continue;
		}
		if(c==val){
			values[a] = val;
			a = i;
			val = d;
			continue;
		}
		if(d==val){
			values[b] = val;
			b = i;
			val = c;
			continue;
//			printf("dobry case %d\n", val);
		}
	}
	values[a] = val;
	values[b] = val;
//	for(i=0;i<2*n;i++)printf("%d ", values[i]);
	for(i=0;i<n;i++){
		int z1 = -1, z2 = -1;
		for(int j=0;j<2*n;j++)
			if(values[j]==i){
				if(z1==-1)z1 = j;
				else
					z2 = j;
			}
		Answer(z1, z2, i);
	}
	return;
}