#include "stations.h"
#include <bits/stdc++.h>
using namespace std;
#define pb push_back
vector<int> adj[1001], col;
int lab = 0;
void dfs(int s, int p, int lab){
col[s]=lab; int x = 0;
for(auto u : adj[s])
if(u!=p) dfs(u,s,lab*10+x),x++;
}
vector<int> label(int n, int k, vector<int> a, vector<int> b)
{
col.clear(), col.resize(n,0); lab = 0;
for(int i = 0; i < n; i++) adj[i].clear();
for (int i = 0; i < n-1; i++)
adj[a[i]].pb(b[i]), adj[b[i]].pb(a[i]);
dfs(0,-1,1); return col;
}
int is_anc(int s, int t){
while(t) {if(s==t) return 1; t/=10; } return 0;
}
int find_next_station(int s, int t, vector<int> c){
if(c.size()==1) return c[0];
for(auto u : c) if(is_anc(u,t)) return u;
return c[0];
}
