#include "islands.h"
#include <bits/stdc++.h>
#include <variant>
using namespace std;
variant<bool, vector<int>> find_journey(int N, int M, vector<int> U, vector<int> V) {
int a=0, b=0, c=0, d=0;
for(int i=0; i<M; i+=2) {
if(U[i]==0) {
if(a<0) a=i, c=i+1;
else if(b<0 && V[a]!=V[i]) b=i, d=i+1;
}
if(V[i]==0) {
if(a<0) a=i+1, c=i;
else if(b<0 && V[a]!=V[i+1]) b=i+1, d=i;
}
}
if(b<0) return false;
vector<int> ret;
ret.push_back(a), ret.push_back(c), ret.push_back(b), ret.push_back(d);
ret.push_back(c), ret.push_back(a), ret.push_back(d), ret.push_back(b);
return ret;
}
