#include "islands.h"
#include<bits/stdc++.h>
using namespace std;
const int N = 1e5+4;
int n,m;
vector<pair<int,int>> adj[N];
variant<bool, vector<int>> first_solve(){
return false;
}
variant<bool, vector<int>> second_solve(){
return false;
}
variant<bool, vector<int>> find_journey(int N, int M, vector<int> U, vector<int> V) {
n = N, m = M;
for (int i=0; i<m; i++)
adj[U[i]].push_back({V[i], i});
bool first = m%2 == 0, second = m%2 == 0;
for (int i=0; i<m; i+=2){
if (U[i] != V[i+1] || U[i+1] != V[i])
first = false;
if (U[i] != U[i+1] || V[i] != V[i+1])
second = false;
}
first = second = false;
if (first)
return first_solve();
else if (second)
return second_solve();
else if (n == 2){
if (adj[0].size() >= 2 && adj[1].size() >= 1){
int a = adj[0][0].second;
int b = adj[0][1].second;
int c = adj[1][0].second;
vector<int> vec = {a, c, b, a, c, b};
return vec;
}
else
return false;
}
else{
int a=0,b=0,c=0,d=0;
for (int i=0; i<m; i++){
if (U[i] == 0 && V[i] == 1) a = i;
if (U[i] == 1 && V[i] == 2) b = i;
if (U[i] == 2 && V[i] == 0) c = i;
if (U[i] == 0 && V[i] == 2) d = i;
}
vector<int> vec = {a, b, c, d, b, a, c, d};
return vec;
}
return false;
}
