#include<bits/stdc++.h>
namespace {
#pragma GCC diagnostic ignored "-Wunused-function"
#include<atcoder/all>
#pragma GCC diagnostic warning "-Wunused-function"
using namespace std;
using namespace atcoder;
#define rep(i,n) for(int i = 0; i < (int)(n); i++)
#define rrep(i,n) for(int i = (int)(n) - 1; i >= 0; i--)
#define all(x) begin(x), end(x)
#define rall(x) rbegin(x), rend(x)
template<class T> bool chmax(T& a, const T& b) { if (a < b) { a = b; return true; } else return false; }
template<class T> bool chmin(T& a, const T& b) { if (b < a) { a = b; return true; } else return false; }
using ll = long long;
using P = pair<int,int>;
using VI = vector<int>;
using VVI = vector<VI>;
using VL = vector<ll>;
using VVL = vector<VL>;

} int main() {
  ios::sync_with_stdio(false);
  cin.tie(0);
  int n, m;
  cin >> n >> m;
  VI p(n);
  rep(i, n) cin >> p[i];
  VI deg(n);
  VVI to(n);
  vector<char> state(n, 1);
  rep(i, n - 1) {
    int a, b;
    cin >> a >> b;
    a--, b--;
    to[a].emplace_back(b);
    to[b].emplace_back(a);
    deg[a]++, deg[b]++;
  }
  priority_queue<P, vector<P>, greater<P>> cand;
  rep(i, n) if (deg[i] == 1) cand.emplace(-p[i], i);
  VI last_added(m);
  rep(i, m) {
    int c;
    cin >> c;
    c--;
    last_added[i] = c;
    state[c] = 2;
  }
  ll ans = 0;
  while (cand.size() || last_added.size()) {
    while (cand.size()) {
      int i = cand.top().second; cand.pop();
      if (state[i] == 1) {
        ans += p[i];
        for (int j : to[i]) if (state[j] == 1) {
          if (--deg[j] == 1) cand.emplace(-p[j], j);
        }
        break;
      }
    }
    VI nxt;
    for (int u : last_added) for (int v : to[u]) if (state[v] == 1) {
      state[v] = 2;
      nxt.emplace_back(v);
    }
    swap(nxt, last_added);
  }
  cout << ans << '\n';
}