#include <bits/stdc++.h>
using namespace std;
#define sz(x) int(x.size())
#define all(x) begin(x), end(x)
const int MAX_N = 1000;
typedef vector<int> vi;
#define pb push_back
vi adj[MAX_N];
int in[MAX_N], out[MAX_N];
int height[MAX_N], timer = 0;
void dfs(int u, int h = 0, int p = -1) {
height[u] = h;
in[u] = timer++;
for (int v : adj[u]) {
if (v != p) dfs(v, h + 1, u);
}
out[u] = timer++;
}
vi label(int n, int k, vi u, vi v) {
for (int i = 0; i < n; i++) {
adj[i].clear();
}
for (int i = 0; i < n - 1; i++) {
adj[u[i]].pb(v[i]);
adj[v[i]].pb(u[i]);
}
dfs(0);
vi l(n);
for (int i = 0; i < n; i++) {
if (height[i] % 2 == 0) {
l[i] = in[i];
} else {
l[i] = out[i];
}
}
vi vals = l;
sort(all(vals));
for (int i = 0; i < n; i++) {
l[i] = int(lower_bound(all(vals), l[i]) - begin(vals));
}
return l;
}
int find_next_station(int s, int t, vi c) {
const int g = sz(c);
int par = -1;
vi c_in, c_out;
if (s < c.back()) {
par = s == 0 ? -1 : c.back();
c_out = c;
c_in.resize(g);
c_in[0] = s + 1;
for (int i = 1; i < g; i++) {
c_in[i] = c_out[i - 1] + 1;
}
} else {
par = c.front();
c_in = c;
c_out.resize(g);
c_out[g - 1] = s - 1;
for (int i = g - 2; i >= 0; i--) {
c_out[i] = c_in[i + 1] - 1;
}
}
for (int i = 0; i < g; i++) {
if (c[i] != par && c_in[i] <= t && t <= c_out[i]) {
return c[i];
}
}
return par;
}
