#include<iostream>
#include<string>
#include<vector>
#include<algorithm>
#include<bitset>
#include<set>
#include<map>
#include<stack>
#include<queue>
#include<deque>
#include<list>
#include<iomanip>
#include<cmath>
#include<cstring>
#include<functional>
#include<cstdio>
#include<cstdlib>
#include<numeric>
using namespace std;

#define repr(i, a, b) for (int i = (int)(a); i < (int)(b); i++)
#define rep(i, n) repr(i, 0, n)
#define INF 2e9
//#define MOD 1000000007
#define MOD 998244353
#define LINF (long long)4e18
#define jck 3.141592

const double EPS = 1e-10;

using ll = long long;
using Pi = pair<int,int>;
using Pl = pair<ll,ll>;

int n;
vector<int> a,b;
vector<vector<int>> G;

ll dp[100010][2];
ll dfs(int u, int k, int p){
    if(p != -1 && G[u].size() == 1){
        if(k == 0) return a[u];
        else return 0;
    }
    if(dp[u][k] != -LINF) return dp[u][k];
    ll res = 0;
    if(k == 0) res = a[u];
    for(int v : G[u]){
        if(v == p) continue;
        if(k == 0){
            res += max(dfs(v,0,u),dfs(v,1,u));
        }
        else res += max(dfs(v,0,u),dfs(v,1,u)+b[u]+b[v]);
    }
    return dp[u][k] = res;
}

int main(){
    cin >> n;
    a.resize(n);
    b.resize(n);
    G.resize(n);
    rep(i,n) cin >> a[i];
    rep(i,n) cin >> b[i];
    rep(i,n-1){
        int u,v; cin >> u >> v;
        u--; v--;
        G[u].push_back(v);
        G[v].push_back(u);
    }
    rep(i,100010)rep(j,2) dp[i][j] = -LINF;
    cout << max(dfs(0,0,-1),dfs(0,1,-1)) << endl;

}