#include<bits/stdc++.h>
using namespace std;
typedef long long ll;
typedef long double ld;
#define REP(i, n) for (int i = 0; i < (n); ++i)
#define REPR(i, n) for (int i = n - 1; i >= 0; --i)
#define FOR(i, m, n) for (int i = m; i < n; ++i)
#define FORR(i, m, n) for (int i = m; i >= n; --i)
#define ALL(v) (v).begin(),(v).end()
template<class T>bool chmax(T &a, const T &b) { if (a<b) { a=b; return 1; } return 0; }
template<class T>bool chmin(T &a, const T &b) { if (b<a) { a=b; return 1; } return 0; }
const ll INF=1LL<<60;
const int inf=(1<<30)-1;
const int mod=1e9+7;
int dx[8]={1,0,-1,0,-1,-1,1,1};
int dy[8]={0,1,0,-1,-1,1,-1,1};
const int nmax=100005;
vector<ll> a(nmax),b(nmax);
vector<vector<int>> e(nmax);
vector<vector<ll>> mem(nmax,vector<ll>(2,-inf));
ll f(int cur,bool ex,int pre=-1){
    if(mem[cur][ex]!=-inf){
        return mem[cur][ex];
    }
    ll res=0;
    if(!ex){
        res+=a[cur];
    }
    for(int to:e[cur]){
        if(to==pre){
            continue;
        }
        if(ex){
            res+=max(f(to,0,cur),f(to,1,cur)+b[cur]+b[to]);
        }
        else{
            res+=max(f(to,0,cur),f(to,1,cur));
        }
    }
    return mem[cur][ex]=res;
}
int main(){
    cin.tie(0);
    ios::sync_with_stdio(false);
    ll n;cin >> 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--;
        e[u].push_back(v);
        e[v].push_back(u);
    }
    cout << max(f(0,0),f(0,1)) << endl;
}