#include<bits/stdc++.h>
using namespace std;
#define fi first
#define se second
#define pb push_back
#define ll long long
#define ld long double
const int N=1e5+50,M=1000;
vector<int>E[N];
int in[N],out[N],depth[N],nc=-1;
void DFS(int u,int parent=0){
in[u]=++nc;depth[u]=depth[parent]+1;
for(auto i:E[u]){
if(i!=parent) DFS(i,u);
}
out[u]=++nc;
}
std::vector<int> label(int n, int k, std::vector<int> u, std::vector<int> v){
for(int i=0;i<n-1;i++){
E[u[i]].pb(v[i]);
E[v[i]].pb(u[i]);
}
int root=0;for(int i=0;i<n;i++) if(E[i].size()==1) root=i;
DFS(root,root);
//for(int i=0;i<n;i++) printf("%i ",depth[i]);printf("\n");
vector<int>lbl;
for(int i=0;i<n;i++){
//lbl.pb(in[i]+M*out[i]);
if(depth[i]&1==1) lbl.pb(in[i]>>1);
else lbl.pb(out[i]>>1);
}
//for(auto i:lbl) printf("%i ",i);printf("\n");
for(int i=0;i<=n;i++) E[i].clear(),in[i]=out[i]=0,nc=-1;
return lbl;
}
int IN(int x){return x%M;}
int OUT(int x){return x/M;}
bool Podstablo(int x,int y){if(IN(x)<=IN(y)&&IN(y)<=OUT(x))return true;return false;}
int find_next_station(int s, int t, std::vector<int> c){
/*int res=c[0];
if(s<t){
for(int i=0;i<c.size();i++){
int u=c[i];
if(u>s) res=u;
}
}
else{
for(int i=0;i<c.size();i++){
int u=c[i];
if(u<s) res=u;
}
}*/
/*int res=c[0];
if(Podstablo(s,t)){
for(auto i:c){
if(Podstablo(i,t)&&!Podstablo(i,s)) res=i;
}
}
else{
for(auto i:c){
if(Podstablo(i,s)) res=i;
}
}*/
s<<=1,t<<=1;for(auto &i:c) i<<=1;
int res=-1,k=c.size(),In[k+10],Out[k+10],I,O;
if(k==1) return c[0]>>1;
if(s<c[0]){
I=s;k--;
for(int i=0;i<k;i++) Out[i]=c[i];
O=Out[k-1]+1;
In[0]=I+1;
for(int i=1;i<k;i++) In[i]=Out[i-1]+1;
if(I<=t&&t<=O){
for(int i=0;i<k;i++) if(In[i]<=t&&t<=Out[i]) res=c[i];
}
else res=c[k];
}
else{
O=s;
for(int i=1;i<k;i++) In[i]=c[i];
I=In[1]-1;
//cerr<<I<<" "<<O<<" "<<t<<endl;
Out[k-1]=O-1;
for(int i=k-2;i>=1;i--) Out[i]=In[i+1]-1;
if(I<=t&&t<=O){
for(int i=1;i<k;i++) if(In[i]<=t&&t<=Out[i]) res=c[i];
}
else res=c[0];
}
res>>=1;
return res;
}
