#include<bits/stdc++.h>
using namespace std;
#include<doll.h>
//#define int long long
int ind;
vector<int> x;
vector<int> y;
/*void answer(vector<int> c, vector<int> x, vector<int> y){
cout << c.size() << "\n";
for(auto e: c){
cout << e << " ";
}
cout << "\n";
cout << x.size() << "\n";
for(int i=0; i<(int)x.size(); i++){
cout << x[i] << " " << y[i] << "\n";
}
}*/
int create_tree(int h, int maxh, int num, vector<int>& a){
if(h==maxh){
if(num>=(int)a.size()) return -1;
return -a[num];
}
int child0=create_tree(h+1, maxh, num, a);
int child1=create_tree(h+1, maxh, num+(1<<h), a);
if(child1==-1) return child0;
x.push_back(-child0);
y.push_back(-child1);
int i=ind;
ind++;
return i;
}
int pow2(int x){
int ans=0;
int p=1;
while(p<x){
ans++;
p*=2;
}
return ans;
}
void create_circuit(int m, vector<int> a){
vector<vector<int> > adi(m+1);
int n=a.size();
for(int i=0; i<n; i++){
adi[a[i]].push_back(a[i+1]);
}
x.clear();
y.clear();
ind=1;
vector<int> c(m+1, 0);
c[0]=a[0];
for(int i=0; i<n; i++){
if(adi[i].size()==0) continue;
if(adi[i].size()==1){
c[i]=adi[i][0];
continue;
}
int maxh=pow2(adi[i].size());
c[i]=-create_tree(0, maxh, 0, adi[i]);
}
answer(c, x, y);
}
/*signed main(){
ios_base::sync_with_stdio(false);
cin.tie(0);
int m, n;
cin >> m >> n;
vector<int> a(n);
for(int i=0; i<n; i++){
cin >> a[i];
}
create_circuit(m, a);
}*/
