#include <bits/stdc++.h>

using namespace std;

#define SZ(x) (int)(x.size())
#define REP(i, n) for(int i=0;i<(n);++i)
#define FOR(i, a, b) for(int i=(a);i<(b);++i)
#define RREP(i, n) for(int i=(int)(n);i>=0;--i)
#define RFOR(i, a, b) for(int i=(int)(a);i>=(int)(b);--i)
#define ALL(a) (a).begin(),(a).end()
#define DUMP(x) cerr<<#x<<" = "<<(x)<<endl
#define DEBUG(x) cerr<<#x<<" = "<<(x)<<" (L"<<__LINE__<<")"<< endl;

using ll = long long;
using vi = vector<int>;
using vvi = vector<vi>;
using vll = vector<ll>;
using vvll = vector<vll>;
using P = pair<int, int>;

const double eps = 1e-8;
const ll MOD = 1000000007;
const int INF = INT_MAX / 2;
const ll LINF = LLONG_MAX / 2;

template <typename T1, typename T2>
bool chmax(T1 &a, const T2 &b) {
  if(a < b) {a = b; return true;}
  return false;
}

template <typename T1, typename T2>
bool chmin(T1 &a, const T2 &b) {
  if(a > b) {a = b; return true;}
  return false;
}

template<typename T1, typename T2>
ostream& operator<<(ostream &os, const pair<T1, T2> p) {
  os << p.first << ":" << p.second;
  return os;
}

template<class T>
ostream &operator<<(ostream &os, const vector<T> &v) {
  REP(i, SZ(v)) {
    if(i) os << " ";
    os << v[i];
  }
  return os;
}

void dfs(int now, int prev, vvi &g, vvll &dp, vll &a, vll &b) {
  for(auto &nxt: g[now]) {
    if(nxt == prev) continue;
    dfs(nxt, now, g, dp, a, b);
  }

  dp[0][now] = a[now];
  for(auto &nxt: g[now]) {
    if(nxt == prev) continue;
    dp[0][now] += max(dp[0][nxt], dp[1][nxt]);
    dp[1][now] += max(dp[0][nxt], dp[1][nxt] + b[nxt] + b[now]);
  }
}

int main() {
  cin.tie(0);
  ios::sync_with_stdio(false);
  cout << fixed << setprecision(10);

  int n; cin >> n;
  vll a(n), b(n);
  REP(i, n) cin >> a[i];
  REP(i, n) cin >> b[i];
  vvi g(n);
  REP(i, n-1) {
    int u, v; cin >> u >> v;
    u--; v--;
    g[u].push_back(v);
    g[v].push_back(u);
  }

  vvll dp(2, vll(n, 0));

  dfs(0, -1, g, dp, a, b);

  cout << max(dp[0][0], dp[1][0]) << endl;


  return 0;
}