#include <bits/stdc++.h>
using namespace std;;
using ll = long long;
using ull = unsigned long long;
using ld = long double;
using uint = unsigned int;
const double EPS = 1e-8;
const int INF = 0x3F3F3F3F;
const ll LINF = 46 * ll(1e17);
const int MOD = 1e9 + 7;
const int maxn = 1e5 + 25;

signed main() { ios::sync_with_stdio(0); cin.tie(0);
    int n, m;
    cin >> n >> m;
    vector<vector<int>> edge(n + 1);
    vector<array<int, 2>> dp(n + 1);
    for (int i = 1; i < n; i++) {
        int u, v;
        cin >> u >> v;
        edge[u].push_back(v);
        edge[v].push_back(u);
    }

    vector<int> has(n + 1);
    while (m--) {
        int x;
        cin >> x;
        has[x] = true;
    }

    function<void(int, int)> dfs = [&] (int u, int p) {
        int cnt = 0;
        for (int v : edge[u]) {
            if (v == p)
                continue;
            dfs(v, u);
            if (has[v])
                dp[u][0] += dp[v][1];
            else {
                cnt++;
                dp[u][0] += dp[v][0];
            }
        }
        if (has[u])
            dp[u][0] = 0;
        else
            dp[u][0]++;
        if (cnt >= 2) {
            for (int v : edge[u])
                if (v != p && !has[v])
                    dp[u][1] += dp[v][0];
            dp[u][1]++;
        }
        else if (cnt == 1) {
            for (int v : edge[u])
                if (v != p && !has[v])
                    dp[u][1] += dp[v][1];
            dp[u][1]++;
        }
    };
    dfs(1, 1);
    cout << dp[1][0] << '\n';
}