#include <bits/stdc++.h>
#define ll long long
using namespace std;
int N;
int A[300001], F[300001], MIN[300001];
int pos, ET[300001];
ll DP[300002];
vector <int> VG[300001];
void DFS(int node, int parent = 0)
{
ET[++pos] = node;
for(int x : VG[node]) if(x != parent) DFS(x, node);
return;
}
int main()
{
ios_base::sync_with_stdio(0), cin.tie(0), cout.tie(0);
cin >> N;
for(int i = 1; i <= N; i++) cin >> A[i];
for(int i = 1; i <= N; i++) cin >> F[i];
MIN[N] = F[N];
for(int i = N - 1; i; i--) MIN[i] = min(MIN[i + 1], F[i]);
int u, v;
for(int i = 1; i < N; i++)
{
cin >> u >> v;
VG[u].push_back(v);
VG[v].push_back(u);
}
if(N > 5000) return 0;
for(int i = 1; i <= N; i++) if(VG[i].size() > 2) return 0;
DFS(1);
for(int i = N; i; i--)
{
DP[ET[i]] = MIN[A[ET[i]] + 1] + DP[ET[i + 1]];
int k = A[ET[i]] + 1;
bool flag = false;
for(int j = i + 1; j <= N; j++)
{
if(A[ET[j]] == (A[ET[j - 1]] + 1))
{
if(flag && (A[ET[j]] >= k)) break;
k = max(k, A[ET[j]] + 1);
}
else if(!A[ET[j]])
{
if(flag && (k != (A[ET[j - 1]] + 1))) break;
if(k > (A[ET[j - 1]] + 1)) break;
k = A[ET[j - 1]] + 1;
flag = true;
}
else break;
if(flag) DP[ET[i]] = min(F[k] + DP[ET[j + 1]], DP[ET[i]]);
else DP[ET[i]] = min(MIN[k] + DP[ET[j + 1]], DP[ET[i]]);
}
}
cout << DP[1] << '\n';
return 0;
}
