#include <bits/stdc++.h>
#define rep(i,n) for(int i = 0; i < (int)(n); i++)
#define rrep(ri,n) for(int ri = (int)(n-1); ri >= 0; ri--)
#define rep2(i,x,n) for(int i = (int)(x); i < (int)(n); i++)
#define rrep2(ri,x,n) for(int ri = (int)(n-1); ri >= (int)(x); ri--)
#define repit(itr,x) for(auto itr = x.begin(); itr != x.end(); itr++)
#define rrepit(ritr,x) for(auto ritr = x.rbegin(); ritr != x.rend(); ritr++)
#define ALL(x) x.begin(), x.end()
using ll = long long;
using namespace std;

void dfs(vector<vector<int>> &tree, vector<int> &b, vector<ll> &po, int now, int bf){
  po.at(now) = (ll)tree.at(now).size() * b.at(now);
  for(auto i : tree.at(now)){
    po.at(now) += b.at(i);
    if(i == bf) continue;
    dfs(tree, b, po, i, now);
  }
}

void fc(vector<vector<int>> &tree, vector<int> &b, vector<ll> &po, vector<bool> &chk, vector<int> &a, int now){
  chk.at(now) = true;
  for(auto i : tree.at(now)){
    if(chk.at(i) == true) continue;
    po.at(i) -= b.at(i);
    if(po.at(i) < a.at(i)){
      fc(tree, b, po, chk, a, i);
    }
  }
}

void dfs2(vector<vector<int>> &tree, vector<int> &a, vector<int> &b, vector<bool> &chk, int now, int bf, ll &ans){
  ll tmp = 0;
  if(chk.at(now) == true){
    ans += a.at(now);
    tmp += a.at(now);
  }
  for(auto i : tree.at(now)){
    if(chk.at(now) == false && chk.at(i) == false){
      ans += b.at(now);
      tmp += b.at(now);
    }
    if(i == bf) continue;
    dfs2(tree, a, b, chk, i, now, ans);
  }
  // cerr << now << " " << tmp << endl;
}

int main(){
  int n;
  cin >> n;
  vector<int> a(n);
  rep(i, n) cin >> a.at(i);
  vector<int> b(n);
  rep(i, n) cin >> b.at(i);
  vector<vector<int>> tree(n, vector<int>());
  rep(i, n-1){
    int a, b;
    cin >> a >> b;
    a--; b--;
    tree.at(a).push_back(b);
    tree.at(b).push_back(a);
  }
  vector<bool> chk(n, false);
  vector<ll> po(n, 0);
  dfs(tree, b, po, 0, -1);
  rep(i, n){
    if(chk.at(i) == true) continue;
    if(po.at(i) < a.at(i)){
      fc(tree, b, po, chk, a, i);
    }
  }
  ll ans = 0;
  dfs2(tree, a, b, chk, 0, -1, ans);
  cout << ans << endl;
  return 0;
}