#include <bits/stdc++.h>
#include "stations.h"
#define ll long long
#define ld long double
#define sp ' '
#define en '\n'
#define smin(a, b) a = min(a, b)
#define smax(a, b) a = max(a, b)
using namespace std;
const int N = 5e5 + 2;
const int mod = 1e9 + 7;
vector<int> label(int n, int k, vector<int> u, vector<int> v) {
vector<vector<int>> g(n);
for (int i = 0; i < n - 1; i++) {
g[u[i]].push_back(v[i]);
g[v[i]].push_back(u[i]);
}
vector<int> ans(n);
int t = 0;
function<void(int, int, int)> Dfs = [&] (int s, int e, int d) {
if (d % 2 == 0) ans[s] = t++;
for (int u : g[s]) if (u != e) Dfs(u, s, d + 1);
if (d % 2 == 1) ans[s] = t++;
};
Dfs(0, 0, 0);
return ans;
}
int find_next_station(int s, int t, vector<int> c) {
int o = c.size();
if (o == 1) return c[0];
for (int i = 0; i < o; i++) if (c[i] == t) return c[i];
if (s < c[0]) {
if (s < t && t < c[0]) return c[0];
for (int i = 1; i < o - 1; i++) {
if (c[i - 1] < t && t < c[i]) return c[i];
}
return c.back();
}
if (c.back() < t && t < s) return c.back();
for (int i = o - 2; i >= 1; i--) {
if (c[i] < t && t < c[i + 1]) return c[i];
}
return c[0];
}
