#include "traffic.h"
#include <bits/stdc++.h>
using namespace std;
#define ll long long
#define pb push_back
#define F first
#define S second
#define INF 1e18
#define all(v) (v).begin(),(v).end()
#define rall(v) (v).rbegin(),(v).rend()
#define pii pair<int,int>
#define pll pair<ll,ll>
#define OK cout<<"Ok"<<endl;
#define MOD (ll)(1e9+7)
#define endl "\n"
const int mxn=1e6+5;
int a[mxn],b[mxn];
vector<int>vt[mxn];
int dfs(int u,int p,int arr[]){
ll ans=0;
for(int v:vt[u]){
if(v!=p){
ll k=dfs(v,u,arr);
ans+=k;
}
}
return ans+arr[u];
}
int LocateCentre(int n, int arr[], int S[], int D[]) {
//bool q=true;
for(int i=0;i<n-1;i++){
vt[S[i]].pb(D[i]);
vt[D[i]].pb(S[i]);
}
ll maxs=2e9,kk=0;
for(int i=0;i<n;i++){
ll sum=dfs(i,-1,arr)-arr[i];
if(sum<maxs){
maxs=sum;
kk=i;
}
}
return kk;
}
