#include using namespace std; template class y_combinator { F f; public: y_combinator(F&& f) : f(std::forward(f)) {} template auto operator()(Args&&... args) const { return f(*this, std::forward(args)...); } }; using ll = long long; using ld = long double; template > using prique = std::priority_queue, U>; template T floor(T a, T b) noexcept { return a / b - (a % b && (a ^ b) < 0); } template T ceil(T a, T b) noexcept { return floor(a + b - 1, b); } template bool chmin(T& x, const T& y) noexcept { return (x > y ? x = y, true : false); } template bool chmax(T& x, const T& y) noexcept { return (x < y ? x = y, true : false); } #define overload4(a, b, c, d, e, ...) e #define rep1(a) for (long long _i = 0; _i < (a); _i++) #define rep2(i, a) for (long long i = 0; i < (a); i++) #define rep3(i, a, b) for (long long i = (a); i < (b); i++) #define rep4(i, a, b, c) for (long long i = (a); i < (b); i += (c)) #define rep(...) overload4(__VA_ARGS__, rep4, rep3, rep2, rep1)(__VA_ARGS__) #define rrep(i, a, b, c) for (long long i = (a); i > (b); i += (c)) #define all(x) std::begin(x), std::end(x) #define rall(x) std::rbegin(x), std::rend(x) #define pb push_back #ifndef LOCAL #define debug(...) #endif void run_case() { int N; cin >> N; vector A(N), B(N); rep(i, N) cin >> A[i]; rep(i, N) cin >> B[i]; vector> G(N); rep(i, 1, N) { int a, b; cin >> a >> b; a--, b--; G[a].pb(b); G[b].pb(a); } vector dp(N, vector(2, 0)); y_combinator([&](auto self, int v, int p = -1) -> void { vector> C; for (int u : G[v]) if (u != p) { self(u, v); C.pb({dp[u][1], u}); dp[v][0] += max(dp[u][0], dp[u][1]); } dp[v][0] += A[v]; for(int u: G[v]) if(u != p) { dp[v][1] += max(dp[u][1] + B[u] + B[v], dp[u][0]); } })(0); debug(dp); cout << max(dp[0][0], dp[0][1]) << "\n"; } int main() { std::ios_base::sync_with_stdio(false); std::cin.tie(nullptr); std::fixed(std::cout).precision(16); int T = 1; while (T--) run_case(); return 0; }