from collections import deque MAX_INT = 10 ** 18 class SegmentTree: """ 非再帰版セグメント木。 更新は「加法」、取得は「最大値」のもの限定。 """ def __init__(self, init_array): n = 1 while n < len(init_array): n *= 2 self.size = n self.array = [[-MAX_INT, -MAX_INT] for _ in range(2 * self.size)] for i, a in enumerate(init_array): self.array[self.size + i][0] = a self.array[self.size + i][1] = i end_index = self.size start_index = end_index // 2 while start_index >= 1: for i in range(start_index, end_index): self._op(self.array[i], self.array[2 * i], self.array[2 * i + 1]) end_index = start_index start_index = end_index // 2 def _op(self, array, left, right): if left[0] > right[0]: array[0] = left[0] array[1] = left[1] elif left[0] < right[0]: array[0] = right[0] array[1] = right[1] else: array[0] = left[0] array[1] = min(left[1], right[1]) def set(self, x, a): index = self.size + x self.array[index][0] = a self.array[index][1] = x while index > 1: index //= 2 self._op(self.array[index], self.array[2 * index], self.array[2 * index+ 1]) def get_max(self, l, r): L = self.size + l; R = self.size + r # 2. 区間[l, r)の最大値を求める s = [- MAX_INT, - MAX_INT] while L < R: if R & 1: R -= 1 self._op(s, s, self.array[R]) if L & 1: self._op(s, s, self.array[L]) L += 1 L >>= 1; R >>= 1 return s def main(): N, M = map(int, input().split()) P = list(map(int, input().split())) next_nodes = [set() for _ in range(N)] for _ in range(N - 1): a, b = map(int, input().split()) next_nodes[a - 1].add(b - 1) next_nodes[b - 1].add(a - 1) C = list(map(int, input().split())) # このまま放置していたら感染されるような場合、いつnodeが感染されるか計算 dists = [MAX_INT] * N queue = deque() for c in C: dists[c - 1] = 0 queue.append(c - 1) while len(queue) > 0: v = queue.popleft() for w in next_nodes[v]: if dists[w] == MAX_INT: dists[w] = dists[v] + 1 queue.append(w) dists_map = {} for i in range(N): d = dists[i] if d not in dists_map: dists_map[d] = [] dists_map[d].append(i) seg_tree = SegmentTree([0] * N) for i in range(N): if len(next_nodes[i]) == 1: seg_tree.set(i, P[i]) answer = 0 enable = [True] * N for t in range(N + 1): if t in dists_map: for index in dists_map[t]: enable[index] = False seg_tree.set(index, 0) s = seg_tree.get_max(0, N) if s[0] >= 1: index = s[1] answer += s[0] seg_tree.set(index, 0) for w in next_nodes[index]: next_nodes[w].remove(index) if len(next_nodes[w]) == 1 and enable[w]: seg_tree.set(w, P[w]) next_nodes[index].clear() print(answer) if __name__ == "__main__": main()