#include<bits/stdc++.h>
using namespace std;
#include"stations.h"
#define N 100005
int st[N],en[N],id[N],cnt[N],sz;
vector<int> g[N];
void dfs(int s,int f,int c){
st[s]=sz++;
cnt[s]=c;
for(auto x:g[s]){
if(x==f)continue;
dfs(x,s,c+1);
}
en[s]=sz++;
}
vector<int> label(int n, int k, vector<int> u, vector<int> v){
int i,a,b,c=0;
vector<int> vec;
for(i=0;i<n-1;i++){
a=u[i],b=v[i];
g[a].push_back(b);
g[b].push_back(a);
}
dfs(0,-1,1);
map<int,int> mp;
for(i=0;i<n;i++)mp[cnt[i]%2?st[i]:en[i]];
for(auto &[x,y]:mp)y=++c;
for(i=0;i<n;i++)vec.push_back(mp[cnt[i]%2?st[i]:en[i]]);
return vec;
}
int find_next_station(int s, int t,vector<int> c){
if(c[0]>s){
//s->st
if(t<s)return c.back();
for(auto x:c)return x;
return c.back();
}
else{
//s->en
if(t>s)return c[0];
for(int i=c.size()-1;i>=0;i--)if(t>=c[i])return c[i];
return c[0];
}
}
