#include <bits/stdc++.h>
#include "doll.h"
using namespace std;
typedef long long LL;
typedef pair<int, int> pii;
int N, M, B, S;
int ID[808080], num;
int L[202020], R[202020];
bool st[202020];
vector<int> A;
void index(int id, int s, int e){
if (s == e || e <= B-N) return;
ID[id] = ++S;
int mid = (s+e)/2;
index(id*2, s, mid);
index(id*2+1, mid+1, e);
}
void f(int id, int s, int e){
if (e <= B-N){
L[ID[id/2]] = -1;
return;
}
if (s == e) return;
int mid = (s+e)/2;
f(id*2, s, mid);
f(id*2+1, mid+1, e);
if (id & 1) R[ID[id/2]] = -ID[id];
else L[ID[id/2]] = -ID[id];
}
void create_circuit(int m, std::vector<int> a){
a.push_back(0);
N = a.size(), M = m, A = a;
for (B=1; B<N; B<<=1);
index(1, 1, B);
f(1, 1, B);
for (int i=0; i<N; i++){
int u=1;
while (1){
if (!st[u]){
if (L[u] == 0){
L[u] = A[i];
st[u] = !st[u];
break;
}
else st[u] = !st[u], u=-L[u];
}
else{
if (R[u] == 0){
R[u] = A[i];
st[u] = !st[u];
break;
}
else st[u] = !st[u], u=-R[u];
}
}
}
vector<int> C(M+1, -1);
vector<int> X, Y;
for (int i=1; i<=S; i++){
X.push_back(L[i]);
Y.push_back(R[i]);
}
answer(C, X, Y);
}
