#include <bits/stdc++.h>
using namespace std;
using pii = pair<int, int>;

int dfs1(int cur, int par, vector<int> &cnt, vector<vector<pii>> &edges) {
    for (auto &[w, nxt] : edges[cur]) {
        if (nxt == par) continue;
        cnt[cur] += dfs1(nxt, cur, cnt, edges);
    }
    return cnt[cur];
}


set<int> ans;
void dfs2(int cur, int par, int pre, vector<int> &cnt, vector<vector<pii>> &edges) {
    int sum = pre;
    for (auto &[w, nxt] : edges[cur]) {
        if (nxt == par) continue;
        sum += cnt[nxt] > 0;
    }
    
    if (sum >= 2) ans.emplace(cur);

    for (auto &[w, nxt] : edges[cur]) {
        if (nxt == par) continue;
        dfs2(nxt, cur, (sum > 0), cnt, edges);
    }
    
    return;
}

inline void solve() {
    int n, k;
    cin >> n >> k;

    vector<vector<pii>> edges(n + 1);
    for (int i = 1, u, v, w; i < n; ++i) {
        cin >> u >> v >> w;
        edges[u].emplace_back(w, v);
        edges[v].emplace_back(w, u);
    }

    ans.clear();
    vector<int> labs(k), cnt(n + 1);
    for (int &i : labs) {
        cin >> i;
        cnt[i] = 1;
        ans.emplace(i);
    }
    
    for (int i = 1; i <= n; ++i)
        sort(edges[i].begin(), edges[i].end());
    
    for (int i : labs) {
        if (size(edges[i]) > 1 && edges[i][0].first == edges[i][1].first) continue;
        if (size(edges[edges[i][0].second]) == 1)
            ans.emplace(edges[i][0].second);

    }
    dfs1(1, 0, cnt, edges);
    dfs2(1, 0, 0, cnt, edges);
    
    cout << size(ans) << '\n';
}

signed main() {
    cin.tie(0)->sync_with_stdio(0);
    int t = 1;

    while (t--)
        solve();
    return 0;
}