#include <bits/stdc++.h>
using namespace std;
template <class F> class y_combinator {
    F f;

   public:
    y_combinator(F&& f) : f(std::forward<F>(f)) {}
    template <class... Args> auto operator()(Args&&... args) const { return f(*this, std::forward<Args>(args)...); }
};
using ll = long long;
using ld = long double;
template <class T, class U = std::less<T>> using prique = std::priority_queue<T, std::vector<T>, U>;
template <class T> T floor(T a, T b) noexcept { return a / b - (a % b && (a ^ b) < 0); }
template <class T> T ceil(T a, T b) noexcept { return floor(a + b - 1, b); }
template <class T> bool chmin(T& x, const T& y) noexcept { return (x > y ? x = y, true : false); }
template <class T> 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, M;
    cin >> N >> M;
    vector<int> P(N);
    rep(i, N) cin >> P[i];
    vector<set<int>> G(N);
    vector<int> deg(N);
    rep(i, 1, N) {
        int a, b;
        cin >> a >> b;
        a--, b--;
        G[a].insert(b);
        G[b].insert(a);
        deg[a]++, deg[b]++;
    }
    vector<int> C(M);
    rep(i, M) cin >> C[i], C[i]--;

    vector<int> vis(N);
    rep(i, M) vis[C[i]] = 1;

    prique<pair<ll, ll>> pq;

    rep(i, N) if (!vis[i] && deg[i] == 1) pq.push({P[i], i});
    ll ans = 0;
    rep(N) {
        debug(pq);
        while (!pq.empty()) {
            auto [p, v] = pq.top();
            pq.pop();
            if (vis[v]) continue;
            else {
                debug(v + 1);
                ans += p;
                deg[v] = 0;
                for (int u : G[v]) {
                    if (--deg[u] == 1) {
                        pq.push({P[u], u});
                    }
                }
                break;
            }
        }

        vector<int> A;
        while (!C.empty()) {
            int v = C.back();
            C.pop_back();
            for (int u : G[v])
                if (!vis[u]) {
                    vis[u] = 1;
                    A.pb(u);
                }
        }
        C = std::move(A);
    }
    cout << ans << "\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;
}