#include <bits/stdc++.h>
#include <variant>
using namespace std;
#ifndef ONLINE_JUDGE
#define dbg(x) cerr << #x << ' '; print(x); cerr << endl;
#else
#define dbg(x)
#endif
void print(int x) {cerr << x;}
void print(long long x) {cerr << x;}
void print(char x) {cerr << x;}
void print(string x) {cerr << x;}
void print(double x) {cerr << x;}
template <class T> void print(vector <T> x);
template <class T> void print(set <T> x);
template <class T> void print(multiset <T> x);
template <class T, class V> void print(pair <T, V> x);
template <class T, class V> void print(map <T, V> x);
template <class T> void print(vector <T> x) {cerr << "[ "; for(auto i : x) {print(i); cerr << ' ';} cerr << "]";}
template <class T> void print(set <T> x) {cerr << "[ "; for(auto i : x) {print(i); cerr << ' ';} cerr << "]";}
template <class T> void print(multiset <T> x) {cerr << "[ "; for(auto i : x) {print(i); cerr << ' ';} cerr << "]";}
template <class T, class V> void print(pair <T, V> x) {cerr << "{"; print(x.first); cerr << ' '; print(x.second); cerr << "}";}
template <class T, class V> void print(map <T, V> x) {cerr << "[ "; for(auto i : x) {print(i); cerr << ' ';} cerr << "]";}
#define ll long long
#define pb push_back
#define ppb pop_back
#define PII pair <int, int>
#define PLL pair <ll, ll>
#define all(v) (v).begin(), (v).end()
#define OK cerr << "OK\n";
#define MP make_pair
const int N0 = 1005, M0 = 2e5 + 5;
int n, m;
PII kayak[N0][N0];
vector <int> u, v;
vector <int> G[N0];
vector <int> color, cycle, road;
int par[N0];
void dfs(int node, int parent){
par[node] = parent;
color[node] = 1;
for(int u : G[node]){
if(u == parent) continue;
if(color[u] == 0){
dfs(u, node);
if(!cycle.empty()) return;
continue;
}
if(color[u] == 1){
int curr = node;
while(curr != par[u]){
cycle.pb(curr);
curr = par[curr];
}
while(curr != -1){
road.pb(curr);
curr = par[curr];
}
return;
}
}
}
variant <bool, vector <int>> find_journey(int N, int M, vector<int> U, vector<int> V){
n = N, m = M, u = U, v = V;
for(int i = 0; i < M; i += 2){
G[u[i]].pb(v[i]);
kayak[u[i]][v[i]] = {i, i + 1};
}
color.assign(N, 0);
dfs(0, -1);
if(cycle.empty()) return false;
return true;
}
