#include <bits/stdc++.h>
#pragma GCC("O3, Ofast, unroll-loop")
#define fi first
#define se second
using namespace std;
using i64 = long long;
using pii = pair<int, i64>;

const int maxn = 300005;

int n, m;
int h[maxn], e[maxn * 2], ne[maxn * 2], w[maxn * 2], idx;
int army[maxn], fa[maxn][20], tsp;
i64 dist[maxn][20];
int vis[maxn], dp[maxn];
int dfn[maxn], ord[maxn], sz[maxn];
std::vector<i64> rest[maxn];

void add(int a, int b, int c) {
	e[idx] = b, ne[idx] = h[a], w[idx] = c, h[a] = idx ++;
}

void dfs1(int u) {
	for (int j = 1; j <= __lg(n); j ++) {
		dist[u][j] = dist[u][j - 1] + dist[fa[u][j - 1]][j - 1];
		fa[u][j] = fa[fa[u][j - 1]][j - 1];
	}
	ord[dfn[u] = ++ tsp] = u, sz[u] = 1;
	for (int i = h[u]; ~i; i = ne[i]) {
		int v = e[i];
		if (v == fa[u][0]) continue;
		dist[v][0] = w[i], fa[v][0] = u;
		dfs1(v);
		sz[u] += sz[v];
	}
}


int main() {
	cin.tie(0);
	cout.tie(0);
	ios::sync_with_stdio(0);

	cin >> n;

	memset(h, -1, sizeof h);
	for (int i = 1; i < n; i ++) {
		int a, b, c;
		cin >> a >> b >> c;
		add(a, b, c);
		add(b, a, c);
	}
	
	cin >> m;
	for (int i = 1; i <= m; i ++)
		cin >> army[i];

	dfs1(1);

	i64 lo = 0, ro = 3e15;
	while (lo <= ro) {
		i64 mid = lo + ro >> 1;

		memset(vis, 0, sizeof vis);
		for (int i = h[1]; ~i; i = ne[i])
			rest[e[i]].clear();

		for (int i = 1; i <= m; i ++) {
			int u = army[i];
			i64 tot = mid;
			for (int j = __lg(n); j >= 0; j -- )
				if (fa[u][j] > 1 && dist[u][j] <= tot)
					tot -= dist[u][j], u = fa[u][j];
			vis[u] = 1;
			if (fa[u][0] == 1) rest[u].push_back(tot);
		}

		memset(dp, 0, sizeof dp);
		std::multiset<pair<i64, int>> usable;
		for (int i = h[1]; ~i; i = ne[i]) {
			int rt = e[i];
			for (int j = dfn[rt] + sz[rt] - 1; j >= dfn[rt]; j --) {
				int u = ord[j];
				if (u != rt) dp[u] = vis[u];
				bool temp = 1, leaf = 1;
				for (int k = h[u]; ~k; k = ne[k]) {
					int v = e[k];
					if (v == fa[u][0]) continue;
					leaf = 0, temp &= dp[v];
				}
				if (!leaf) dp[u] |= temp;
			}

			sort(rest[rt].begin(), rest[rt].end());
			for (auto t : rest[rt])
				usable.insert({t - w[i], rt});
		}

		bool ok = 1;
		for (int i = h[1]; ~i; i = ne[i]) {
			int u = e[i];
			if (!dp[u]) {
				auto it = usable.lower_bound({w[i], 0});
				i64 val = 1e18;
				for (auto t : rest[u])
					if (usable.find({t - w[i], u}) != usable.end()) {
						val = t - w[i];
						break;
					}
				if (it == usable.end() && val == 1e18) {
					ok = false;
					break;
				}
				if (it == usable.end() || val < (*it).fi)
					usable.erase(usable.find({val, u}));
				else usable.erase(it);
			}
		}

		if (ok) ro = mid - 1;
		else lo = mid + 1;
	}

	if (ro == 3e15) cout << -1 << endl;
	else cout << ro + 1 << endl;

	return 0;
}
/*
7
1 2 193156
1 3 543535
2 4 458552
4 5 777976
3 6 475533
1 7 876969
3
7 4 7 
*/