#include <bits/stdc++.h>
#include "doll.h"
using namespace std;
#define ll long long
#define vb vector<bool>
#define pb push_back
#define ff(aa, bb, cc) for(int aa = bb; aa < cc; aa++)
#define vl vector<ll>
#define pll pair<ll, ll>
#define fi first
#define se second
#define ed "\n"
#define all(aaa) aaa.begin(), aaa.end()
#define rall(aaa) aaa.rbegin(), aaa.rend()
ll MOD = 1e9+7;
/*
namespace {
constexpr int P_MAX = 20000000;
constexpr int S_MAX = 400000;
int M, N;
std::vector<int> A;
bool answered;
int S;
std::vector<int> IC, IX, IY;
int read_int() {
int x;
if (scanf("%d", &x) != 1) {
fprintf(stderr, "Error while reading input\n");
exit(1);
}
return x;
}
void wrong_answer(const char *MSG) {
printf("Wrong Answer: %s\n", MSG);
exit(0);
}
void simulate() {
if (S > S_MAX) {
char str[50];
sprintf(str, "over %d switches", S_MAX);
wrong_answer(str);
}
for (int i = 0; i <= M; ++i) {
if (!(-S <= IC[i] && IC[i] <= M)) {
wrong_answer("wrong serial number");
}
}
for (int j = 1; j <= S; ++j) {
if (!(-S <= IX[j - 1] && IX[j - 1] <= M)) {
wrong_answer("wrong serial number");
}
if (!(-S <= IY[j - 1] && IY[j - 1] <= M)) {
wrong_answer("wrong serial number");
}
}
int P = 0;
std::vector<bool> state(S + 1, false);
int pos = IC[0];
int k = 0;
FILE *file_log = fopen("out", "w");
fprintf(file_log, "0\n");
for (;;) {
fprintf(file_log, "%d\n", pos);
if (pos < 0) {
if (++P > P_MAX) {
fclose(file_log);
char str[50];
sprintf(str, "over %d inversions", P_MAX);
wrong_answer(str);
}
state[-pos] = !state[-pos];
pos = state[-pos] ? IX[-(1 + pos)] : IY[-(1 + pos)];
} else {
if (pos == 0) {
break;
}
if (k >= N) {
fclose(file_log);
wrong_answer("wrong motion");
}
if (pos != A[k++]) {
fclose(file_log);
wrong_answer("wrong motion");
}
pos = IC[pos];
}
}
fclose(file_log);
if (k != N) {
wrong_answer("wrong motion");
}
for (int j = 1; j <= S; ++j) {
if (state[j]) {
wrong_answer("state 'Y'");
}
}
printf("Accepted: %d %d\n", S, P);
}
} // namespace
void answer(std::vector<int> C, std::vector<int> X, std::vector<int> Y) {
if (answered) {
wrong_answer("answered not exactly once");
}
answered = true;
// check if input format is correct
if ((int)C.size() != M + 1) {
wrong_answer("wrong array length");
}
if (X.size() != Y.size()) {
wrong_answer("wrong array length");
}
S = X.size();
IC = C;
IX = X;
IY = Y;
}
*/
void create_circuit(int m, std::vector<int> a) {
vl count(m+1);
ll n = a.size();
ff(i, 0, n){
count[a[i]]++;
}
map<ll, ll> id;
vector<int> connections(m+1, 0);
vector<int> x, y;
ll switch_id = 0; ////////////////////////////////////////////////////////
connections[0] = a[0];
//cout << "START " << 0 << " TO " << a[0] << ed << ed;
ff(i, 0, n){
//cout << a[i] << " ";
if(count[a[i]] == 1){
//cout << "ONE -> ";
if(i == n-1){
//cout << "LAST TO ";
connections[a[i]] = 0;
//cout << connections[a[i]] << ed;
}
else{
//cout << "CONNECTED TO " << a[i+1] << ed;
connections[a[i]] = a[i+1];
}
//cout << connections[a[i]] << ed;
}
else if(count[a[i]] == 2){
//cout << "TWO " << " ";
if(i == n-1){ //asumimos q ya se creo switch
//cout << "LAST -> switch " << connections[a[i]] << " TO " << 0 << ed;
y[id[a[i]]] = 0;
continue;
}
if(id[a[i]] == 0){ //nuevo
//cout << "NEW -> switch " << -(switch_id+1) << " TO " << a[i+1] << ed;
connections[a[i]] = -(switch_id+1);
x.pb(0);
y.pb(0);
id[a[i]] = switch_id+1;
x[switch_id] = a[i+1];
switch_id++;
//cout << "X AND Y === " << x[id[a[i]]-1] << " " << y[id[a[i]]-1] << "UK" << ed;
}
else{ //2da salida
//cout << "SECOND -> switch " << connections[a[i]] << " TO " << a[i+1] << ed;
y[id[a[i]]-1] = a[i+1];
//cout << "X AND Y === " << x[id[a[i]]-1] << " " << y[id[a[i]]-1] << ed;
}
}
//cout << ed << ed;
}
/*ff(i, 0, m+1){
cout << connections[i] << " ";
}
cout << ed << ed;
ff(i, 0, x.size()){
cout << x[i] << " ";
}
cout << ed;
ff(i, 0, x.size()){
cout << y[i] << " ";
}
cout << ed;*/
answer(connections, x, y);
}
/*
int main() {
M = read_int();
N = read_int();
A.resize(N);
for (int k = 0; k < N; ++k) {
A[k] = read_int();
}
answered = false;
create_circuit(M, A);
if (!answered) {
wrong_answer("answered not exactly once");
}
FILE *file_out = fopen("out.txt", "w");
fprintf(file_out, "%d\n", S);
for (int i = 0; i <= M; ++i) {
fprintf(file_out, "%d\n", IC[i]);
}
for (int j = 1; j <= S; ++j) {
fprintf(file_out, "%d %d\n", IX[j - 1], IY[j - 1]);
}
fclose(file_out);
simulate();
return 0;
}
*/
