#include "stations.h"
#include <bits/stdc++.h>
using namespace std;
#define pb push_back
vector<int> label(int n, int k, vector<int> U, vector<int> V) {
vector<vector<int>> adj(n);
for (int i = 0; i < n - 1; i++) {
adj[U[i]].pb(V[i]);
adj[V[i]].pb(U[i]);
}
vector<int> res(n);
int tt = 0;
auto dfs = [&](auto&& self, int u = 0, int par = -1, bool flag = false) -> void {
if (!flag) res[u] = ++tt;
for (int v : adj[u]) {
if (v == par) continue;
self(self, v, u, flag ^ 1);
}
if (flag) res[u] = ++tt;
};
dfs(dfs);
return res;
}
int find_next_station(int s, int t, vector<int> c) {
if (c.size() == 1) return c.front();
c.pb(s);
sort(c.begin(), c.end());
if (c.back() == s) {
for (int i = 1; i < (int)(c.size()) - 1; i++) {
if (c[i] <= t && t < c[i + 1]) return c[i];
}
return c.front();
} else if (c.front() == s) {
for (int i = 1; i < (int)(c.size()) - 1; i++) {
if (c[i - 1] < t && t <= c[i]) return c[i];
}
return c.back();
} else throw runtime_error("wrong construction");
}
