#ifndef LOCAL
#pragma GCC Optimize("O3,Ofast,unroll-loops")
#pragma GCC Target("bmi,bmi2,avx,avx2")
#endif
#include <bits/stdc++.h>
using namespace std;
using ll = long long;
using ld = long double;
#define int ll
#define f first
#define s second
#define mp make_pair
#define pb push_back
#define pii pair<int, int>
#define all(x) (x).begin(), (x).end()
#define rall(x) (x).rbegin() (x).rend()
#ifndef LOCAL
#define endl "\n"
#endif
mt19937 rnd(11);
void solve() {
int n;
cin >> n;
vector<int> a(n);
for (auto &x : a) {
cin >> x;
}
vector<int> f(n);
for (auto &x : f) {
cin >> x;
}
f.insert(f.begin(), 0);
vector<int> suffmin = f;
for (int i = n; i > 0; --i) {
suffmin[i - 1] = min(suffmin[i], suffmin[i - 1]);
}
vector<vector<int>> graph(n);
for (int i = 1; i < n; ++i) {
int a, b;
cin >> a >> b;
--a; --b;
graph[a].pb(b);
graph[b].pb(a);
}
vector<map<int, int>> A(n), B(n);
auto get = [&](int ind, int x, bool eq = false) {
int answer = 1e18;
if (B[ind].count(x) && eq) {
answer = B[ind][x];
}
for (auto &y : A[ind]) {
if (y.f <= x) {
answer = min(answer, y.s);
}
}
return answer;
};
auto dfs = [&](int v, int prev, auto &&self) -> int {
int ans = v;
A[ans][0] = suffmin[a[v] + 1];
A[ans][a[v] + 1] = 0;
for (auto &u : graph[v]) {
if (u != prev) {
int res = self(u, v, self);
int delta = get(res, 0);
if (a[u] > 0 && a[u] != a[v] + 1) {
for (auto &x : A[ans]) {
x.s += delta;
}
for (auto &x : B[ans]) {
x.s += delta;
}
} else {
if (a[u] > 0) {
for (auto &x : A[res]) {
A[ans][x.f] = get(ans, x.f);
}
for (auto &x : B[res]) {
B[ans][x.f] = get(ans, x.f, true);
}
for (auto &x : A[ans]) {
x.s += get(res, x.f);
}
for (auto &x : B[ans]) {
x.s += get(res, x.f, true);
}
} else {
int k = a[v] + 1;
int now = get(ans, k, true);
B[ans][k] = now + get(res, k, true);
for (auto &x : A[ans]) {
x.s += delta;
}
for (auto &x : B[ans]) {
if (x.f != k) {
x.s += delta;
}
}
}
}
}
}
for (auto &x : B[ans]) {
A[ans][0] = min(A[ans][0], x.s + f[x.f]);
}
for (auto &x : A[ans]) {
A[ans][0] = min(A[ans][0], x.s + suffmin[x.f]);
}
return ans;
};
auto ans = dfs(0, 0, dfs);
cout << get(ans, 0) << endl;
}
signed main() {
#ifdef LOCAL
freopen("in.txt", "r", stdin);
freopen("out.txt", "w", stdout);
#else
ios::sync_with_stdio(false);
cin.tie(0);
#endif
int t = 1;
// cin >> t;
while (t--) {
solve();
}
}
