#include <bits/stdc++.h>
#pragma GCC optimize("O3,unroll-loops")
using namespace std;
using LL = long long;

void O_o() {
	int n, k;
	cin >> n >> k;
	
	vector<vector<int>> adj(n);
	for (int i = 0; i < n - 1; i++) {
		int u, v, val;
		cin >> u >> v >> val;
		u--, v--;
		adj[v].push_back(u);
		adj[u].push_back(v);
	}

	vector<int> tag(n), ok(n);
	for (int i = 0; i < k; i++) {
		int x;
		cin >> x;
		x--;
		tag[x] = ok[x] = 1;
	}
	
	vector<int> sub(n);
	auto dfs = [&] (auto dfs, int x, int lst) -> void {
		if (tag[x]) {
			sub[x] = 1;
		}
		for (auto y : adj[x]) {
			if (y == lst) {
				continue;
			}
			dfs(dfs, y, x);
			if (sub[y]) {
				sub[x] = 1;
			}
		}
	};
	dfs(dfs, 0, -1);

	auto dfs2 = [&] (auto dfs2, int x, int lst, int f) -> void {
		vector<int> a;
		for (auto y : adj[x]) {
			if (y == lst) {
				continue;
			}
			if (sub[y]) {
				a.push_back(y);
			}
		}
		if (a.size() > 1 || (a.size() == 1 && f)) {
			ok[x] = 1;
		}
		for (auto y : adj[x]) {
			if (y == lst) {
				continue;
			}
			int tr = f;
			if (tag[x] || a.size() > 2 || (a.size() == 1 && a[0] != y)) {
				tr = 1;
			}
			dfs2(dfs2, y, x, tr);
		}
	};
	dfs2(dfs2, 0, -1, 0);
	
	int res = 0;
	for (int i = 0; i < n; i++) {
		if (ok[i]) {
			res++;
		}
	}
	cout << res << '\n';
	
}

int main(){
	ios::sync_with_stdio(false);
	cin.tie(nullptr);
	
	int t = 1;
		
	while (t--) {
		O_o();
	}

	return 0;
}