#include "traffic.h"
#include <bits/stdc++.h>
using namespace std;
// macros
typedef long long ll;
typedef long double ld;
typedef pair<int, int> ii;
typedef pair<ll, ll> lll;
typedef tuple<int, int, int> iii;
typedef vector<int> vi;
typedef vector<ii> vii;
typedef vector<iii> viii;
typedef vector<ll> vll;
typedef vector<lll> vlll;
#define REP(a,b,c) for(int a=int(b); a<int(c); a++)
#define RE(a,c) REP(a,0,c)
#define RE1(a,c) REP(a,1,c+1)
#define REI(a,b,c) REP(a,b,c+1)
#define REV(a,b,c) for(int a=int(c-1); a>=int(b); a--)
#define FOR(a,b) for(auto& a : b)
#define all(a) a.begin(), a.end()
#define INF (2e9+1)
#define EPS 1e-9
#define pb push_back
#define popb pop_back
#define fi first
#define se second
int LocateCentre(int N, int pp[], int S[], int D[]) {
vector<vi> adj; adj.resize(N);
vi sz; sz.assign(N,0);
vi par; par.assign(N,-1);
// fill adj
RE(i,N-1) adj[S[i]].pb(D[i]);
RE(i,N-1) adj[D[i]].pb(S[i]);
function<void(int,int)> fillSize = [&](int u, int p) {
sz[u] = pp[u];
par[u] = p;
FOR(v,adj[u]) {
if(v == p) continue;
fillSize(v,u);
sz[u] += sz[v];
}
};
function<int(int)> getCost = [&](int u) {
int res = sz[0] - sz[u];
FOR(v,adj[u]) {
if(v == par[u]) continue;
res = max(res, sz[v]);
}
return res;
};
fillSize(0,-1);
int bst = 0, bstCost = getCost(0);
RE(i,N) if(getCost(i) < bstCost) {
bstCost = getCost(i);
bst = i;
}
return bst;
}
