#include <bits/stdc++.h>

using namespace std;
#define int long long
#define endl '\n'
#define PII pair<int, int>
const int N = 2e5 + 5;
int n, m, ans, vis[N], dp[N][4];
vector<int> e[N];
void dfs(int u, int fa, int ok)
{
    if (ok == 2)
    {
        return;
    }
    ans++;
    if (vis[u])
    {
        int cnt = 0;
        for (auto to : e[u])
            if (to != fa)
                cnt++;
        if (cnt >= 2)
        {
            for (auto to : e[u])
                if (to != fa)
                    dfs(to, u, ok);
        }
        else
        {
            for (auto to : e[u])
                if (to != fa)
                {
                    ans--;
                    dfs(to, u, ok + 1);
                }
        }
    }
    else
    {
        for (auto to : e[u])
            if (to != fa)
                dfs(to, u, ok);
    }
}

void solve()
{
    cin >> n >> m;
    for (int i = 1; i < n; i++)
    {
        int u, v;
        cin >> u >> v;
        e[u].push_back(v);
        e[v].push_back(u);
    }
    // for (int i = 2; i <= n; i++)
    //     if (e[i].size() == 1)
    //         vis[i] = 1;
    for (int i = 1; i <= m; i++)
    {
        int x;
        cin >> x;
        vis[x] = 1;
    }
    dfs(1, 0, 0);
    cout << ans << endl;
}

signed main()
{
    ios::sync_with_stdio(0), cin.tie(0), cout.tie(0);
    int t = 1;
    while (t--)
        solve();
    return 0;
}