from collections import deque, defaultdict

def min_white_nodes(n, k, black_nodes, edges):
    # 构建树的邻接表
    graph = defaultdict(list)
    for u, v in edges:
        graph[u].append(v)
        graph[v].append(u)

    # 标记初始黑色节点
    is_black = [False] * (n + 1)
    for b in black_nodes:
        is_black[b] = True

    # 找出需要染白的最少点
    visited = [False] * (n + 1)
    queue = deque()
    white_count = 0

    # 多源 BFS，从黑色点出发
    for b in black_nodes:
        queue.append(b)
        visited[b] = True

    while queue:
        node = queue.popleft()
        for neighbor in graph[node]:
            if not visited[neighbor]:
                if is_black[node]:  # 黑色传播的点
                    is_black[neighbor] = True
                else:  # 灰色传播的点需要控制
                    white_count += 1
                queue.append(neighbor)
                visited[neighbor] = True

    return white_count

# 读取输入
n, k = map(int, input().split())
black_nodes = list(map(int, input().split()))
edges = [tuple(map(int, input().split())) for _ in range(n - 1)]

# 求解
result = min_white_nodes(n, k, black_nodes, edges)
print(result)