#include <bits/stdc++.h>
 
const double pi = 3.141592653589793238462643383279;
using namespace std;

//typedef
//------------------------------------------
typedef vector<int> VI;
typedef vector<VI> VVI;
typedef vector<string> VS;
typedef pair<int, int> PII;
typedef pair<long long, long long> PLL;
typedef pair<int, PII> TIII;
typedef long long LL;
typedef unsigned long long ULL;
typedef vector<LL> VLL;
typedef vector<VLL> VVLL;
 
 
//container util
//------------------------------------------
#define ALL(a)  (a).begin(),(a).end()
#define RALL(a) (a).rbegin(), (a).rend()
#define PB push_back
#define MP make_pair
#define SQ(a) ((a)*(a))
#define EACH(i,c) for(typeof((c).begin()) i=(c).begin(); i!=(c).end(); ++i)
#define EXIST(s,e) ((s).find(e)!=(s).end())
#define SORT(c) sort((c).begin(),(c).end())
 
 
//repetition
//------------------------------------------
#define FOR(i,s,n) for(int i=s;i<(int)n;++i)
#define REP(i,n) FOR(i,0,n)
#define MOD 1000000007
 
 
#define rep(i, a, b) for(int i = a; i < (b); ++i)
#define trav(a, x) for(auto& a : x)
#define all(x) x.begin(), x.end()
#define sz(x) (int)(x).size()
 
typedef long long ll;
typedef pair<int, int> pii;
typedef vector<int> vi;
 
#define chmin(x,y) x=min(x,y)
#define chmax(x,y) x=max(x,y)

const long double EPS = 1e-6, PI = acos((long double)-1);

//ここから編集
vector<ll> a(101010);
vector<ll> b(101010);
vector<vector<int>> g(101010);
ll dp[2][101010];

void dfs(int v, int p=-1){

  for(auto u: g[v]){
    if(u == p) continue;

    dfs(u, v);
  }

  if(p != -1 && g[v].size() == 1){
    dp[0][v] = a[v];
    dp[1][v] = 0;
  }else{
    /* 頂点を削除する場合 */
    dp[0][v] = a[v];
    for(auto u: g[v]){
      if(u == p) continue;
      dp[0][v] += max(dp[0][u], dp[1][u]);
    }

    /* 頂点を残す場合 */
    dp[1][v] = 0;
    for(auto u: g[v]){
      if(u == p) continue;
      dp[1][v] += max(dp[0][u], dp[1][u] + b[u] + b[v]);
    }
  }
}
int main() {
  cin.tie(0);
  ios::sync_with_stdio(false);
  cout << fixed << setprecision(4);

  int N; cin >> N;
  REP(i,N) cin >> a[i];
  REP(i,N) cin >> b[i];
  REP(i,N-1){
    int v, u; cin >> v >> u;
    v--; u--;
    g[v].push_back(u);
    g[u].push_back(v);
  }
  REP(i,101010) dp[0][i] = dp[1][i] = -(1LL<<60); 
  dfs(0);
  cout << max(dp[0][0], dp[1][0]) << endl;
  return 0;
}