#include <bits/stdc++.h>
using namespace std;
#define in(i) cin >> i
#define out(o) cout << o
vector<int> parent;
vector<int> sz;
int find(int v) {
if (v == parent[v]) return v;
return parent[v] = find(parent[v]);
}
void unite(int a, int b) {
a = find(a);
b = find(b);
if (a == b) return;
if (sz[a] > sz[b]) swap(a, b);
parent[a] = b;
sz[b] += sz[a];
}
vector<int> check_validity(int N, vector<int> X, vector<int> Y, vector<int> S, vector<int> E, vector<int> L, vector<int> R) {
int M = X.size(); // = Y.size()
int Q = S.size(); // = E.size() = L.size() = R.size()
parent.resize(N);
sz.resize(N, 1);
vector<int> ans(Q);
if (N <= 3000 && M <= 6000 && Q <= 3000) {
// S1, S2
for (int i = 0; i < Q; i++) {
int l = L[i];
int r = R[i];
int s = S[i];
int e = E[i];
for (int j = 0; j < N; j++) parent[j] = j, sz[j] = 1;
for (int j = 0; j < M; j++) {
int x = X[j];
int y = Y[j];
if (l <= min(x, y)) unite(x, y);
}
vector<int> works(N, 0);
for (int j = 0; j < N; j++) if (find(s) == find(j)) works[j]++;
for (int j = 0; j < N; j++) parent[j] = j, sz[j] = 1;
for (int j = 0; j < M; j++) {
int x = X[j];
int y = Y[j];
if (r >= max(x, y)) unite(x, y);
}
for (int j = 0; j < N; j++) if (find(e) == find(j)) works[j]++;
ans[i] = +(*max_element(works.begin(), works.end()) == 2);
}
}
return ans;
}
