#include "doll.h"
typedef std::vector<int> vi;
int n, m, s;
vi X, Y, C;
int L[400010], R[400010], rt;
bool state[400010];
int B[200010];
int make_tree(){
vi Q, P;
for(int i=1; i<=n; i++) Q.push_back(i);
do{
for(int i=0, sz=Q.size(); i<sz; i+=2){
s++;
int a=Q[i], b=(i+1<sz ? Q[i+1] : 0);
L[s]=a, R[s]=b;
P.push_back(-s);
}
Q.clear(); Q=P; P.clear();
} while(Q.size()>1U);
return -Q[0];
}
int find(int v=-rt){
if(v>=0) return v;
int ret=find(state[-v] ? L[-v] : R[-v]);
state[-v]=!state[-v];
return ret;
}
int f(int x){
if(x==0) return -rt;
if(x<0) return x;
return B[x];
}
void create_circuit(int M, vi A) {
n=A.size(); m=M;
A.push_back(0);
C.resize(m+1), C[0]=A[0];
rt=make_tree();
for(int i=1; i<=m; i++) C[i]=-rt;
int pos=1;
while(pos<=n){
int now=find();
if(now==0) continue;
B[now]=A[pos]; pos++;
}
for(int i=1; i<=s; i++){
X.push_back(f(R[i]));
Y.push_back(f(L[i]));
}
answer(C, X, Y);
}
