#include "stations.h"
#include <bits/stdc++.h>
using namespace std;
vector<int> label(int n, int k, vector<int> u, vector<int> v) {
vector<int> lbl(n);
for (int i=0; i<n; i++){
lbl[i]=i;
}
return lbl;
}
static inline bool is_descendant(int root, int node) {
if (node==root) return true;
while (node>root){
node=(node-1)/2;
if (node==root) return true;
}
return false;
}
int find_next_station(int s, int t, vector <int> c){
if (c.size()==1){return c[0];}
else if(s==0){
if (is_descendant(c[0], t)) return c[0];
return c[1];
}
else{
if (is_descendant(c[1], t)) return c[1];
if (c.size()==3 && is_descendant(c[2], t)) return c[2];
return c[0];
}
}
