#include <iostream>
#include <vector>
#include <traffic.h>
using namespace std;
#define MAXN 1000005
#define FOR(i, a, b) for(int i = a; i <= b; i++)
int t = 0, sum[MAXN], p[MAXN];
pair<int, int> r = make_pair(-1, 2000000005);
vector<int> e[MAXN];
int dfs(int i = 0, int par = 0){
sum[i] = p[i];
int mx = 0;
for(int i2 : e[i]) if(i2 != par){
sum[i] += dfs(i2, i);
mx = max(mx, sum[i2]);
}
mx = max(mx, t - sum[i]);
if(mx < r.second){
r.first = i;
r.second = mx;
}
return sum[i];
}
int LocateCentre(int N, int P[], int S[], int D[]){
if(N == 1) return 0;
FOR(i, 0, N - 1) t += P[i], p[i] = P[i];
FOR(i, 0, N - 2) {
e[S[i]].push_back(D[i]);
e[D[i]].push_back(S[i]);
}
dfs();
return r.first;
}
