#include <iostream>
#include <vector>
#include <tuple>
#include <queue>
using namespace std;
using ll = long long;
int main() {
ios::sync_with_stdio(false);
cin.tie(nullptr);
int n, m, k;
cin >> n >> m >> k;
vector<vector<pair<int, ll> > > adj(n + 1);
while (m--) {
int u, v;
ll c;
cin >> u >> v >> c;
adj[u].emplace_back(v, c);
adj[v].emplace_back(u, c);
}
vector<bool> special(n + 1);
for (ll i = 0; i < k; ++i) {
int x;
cin >> x;
special[x] = true;
}
auto dijkstra_all = [&] {
priority_queue<pair<ll, int> > pq;
vector<ll> dist(n + 1, 1e18);
vector<int> per(n + 1);
for (int i = 1; i <= n; ++i) {
if (special[i]) {
pq.emplace(0, i);
per[i] = i;
dist[i] = 0;
}
}
while (!pq.empty()) {
auto [d, u] = pq.top();
pq.pop();
if (-d != dist[u])
continue;
for (auto &[v, c]: adj[u]) {
if (dist[u] + c < dist[v]) {
per[v] = per[u];
dist[v] = dist[u] + c;
pq.emplace(-dist[v], v);
}
}
}
ll ans = 1e18;
int a = 0, b = 0;
for (int u = 1; u <= n; ++u) {
for (auto &[v, c]: adj[u]) {
if (per[u] != per[v] && dist[u] + dist[v] + c < ans) {
ans = dist[u] + dist[v] + c;
a = u;
b = v;
}
}
}
return tuple{ans, a, b};
};
auto dijkstra = [&](int x)-> pair<ll, int> {
priority_queue<pair<ll, int> > pq;
vector<ll> dist(n + 1, 1e18);
dist[x] = 0;
pq.emplace(0, x);
while (!pq.empty()) {
auto [d, u] = pq.top();
pq.pop();
if (special[u]) return {-d, u};
if (dist[u] != d) continue;
for (auto &[v, c]: adj[u]) {
if (dist[u] + c < dist[v]) {
dist[v] = dist[u] + c;
pq.emplace(-dist[v], v);
}
}
}
return {1e18, 0};
};
ll ans = 1e18;
auto [cost1, x, y] = dijkstra_all();
special[x] = special[y] = false;
ans = min(ans, cost1 + get<0>(dijkstra_all()));
auto [cost2, a] = dijkstra(x);
special[a] = false;
ans = min(ans, cost2 + dijkstra(y).first);
special[a] = true;
auto [cost3, b] = dijkstra(y);
special[b] = false;
ans = min(ans, cost2 + dijkstra(x).first);
cout << ans << '\n';
}
/*
5 4 4
1 2 1
3 4 2
4 5 5
5 3 8
3 1 5 2
*/
/*
6 6 4
1 2 5
2 4 7
4 6 50
6 5 3
1 5 15
3 5 6
1 5 4 6
*/
