#include <iostream>
#include <vector>
#include <queue>
#include <utility>
using namespace std;
typedef pair<long long, int> P;
int main(){
    ios::sync_with_stdio(false);
    cin.tie(nullptr);
    int N;
    cin >> N;
    vector<long long> a(N), b(N);
    for(int i = 0; i < N; i++) cin >> a[i];
    for(int i = 0; i < N; i++) cin >> b[i];
    vector<int> G[N];
    for(int i = 0; i < N - 1; i++){
        int u, v;
        cin >> u >> v;
        u--;
        v--;
        G[u].push_back(v);
        G[v].push_back(u);
    }
    vector<long long> size(N);
    for(int i = 0; i < N; i++){
        size[i] = G[i].size();
    }
    vector<int> used(N, 0);
    vector<long long> score(N, 0);
    long long sum = 0;
    for(int i = 0; i < N; i++){
        score[i] = size[i] * b[i];
        sum += score[i];
        for(int j: G[i]) score[i] += b[j];
    }
    priority_queue<P> pq;
    for(int i = 0; i < N; i++){
        score[i] = a[i] - score[i];
        if(score[i] > 0) pq.push(P(score[i], i));
    }
    while(!pq.empty()){
        P v = pq.top();
        pq.pop();
        long long temp = v.first;
        int ind = v.second;
        if(used[ind] == 1) continue;
        used[ind] = 1;
        sum += temp;
        for(int j: G[ind]){
            score[j] += b[ind];
            if(score[j] > 0 && used[j] == 0) pq.push(P(score[j], j));
        }
    }
    cout << sum << endl;
}