/**
* author: Haunted_Cpp
**/
#include <bits/stdc++.h>
using namespace std;
#pragma GCC optimize("Ofast")
#pragma GCC target("fma,sse,sse2,sse3,ssse3,sse4,popcnt,abm,mmx,avx,avx2,tune=native")
#pragma GCC optimize("unroll-loops")
template<typename T> ostream &operator << (ostream &os, const vector<T> &v) { os << '{'; string sep; for (const auto &x : v) os << sep << x, sep = ", "; return os << '}'; }
template<typename T, size_t size> ostream &operator << (ostream &os, const array<T, size> &arr) { os << '{'; string sep; for (const auto &x : arr) os << sep << x, sep = ", "; return os << '}'; }
template<typename A, typename B> ostream &operator << (ostream &os, const pair<A, B> &p) { return os << '(' << p.first << ", " << p.second << ')'; }
void debug_out() { cerr << endl; }
template<typename Head, typename... Tail> void debug_out(Head H, Tail... T) { cerr << ' ' << H; debug_out(T...); }
#ifdef LOCAL
#define debug(...) cerr << "(" << #__VA_ARGS__ << "):", debug_out(__VA_ARGS__)
#else
#define debug(...) 47
#endif
const int MAX_N = 1e5 + 5;
const int INF = 1e9 + 5;
vector<vector<pair<int, int>>> g(MAX_N);
int main () {
ios::sync_with_stdio(0);
cin.tie(0);
int n, m, k;
cin >> n >> m >> k;
for (int i = 0; i < m; i++) {
int st, et, w;
cin >> st >> et >> w;
--st; --et;
g[st].emplace_back(et, w);
g[et].emplace_back(st, w);
}
vector<bool> is_special(n);
for (int i = 0; i < k; i++) {
int foo;
cin >> foo;
--foo;
is_special[foo] = true;
}
int res = 0;
int add = 0;
auto Dijkstra = [&](bool basic_graph) {
priority_queue<pair<int, int>, vector<pair<int, int>>, greater<pair<int, int>>> pq;
vector<int> dist(n, INF);
vector<int> root(n, -1);
vector<pair<int, int>> closest_vertex(n, {INF, -1});
for (int i = 0; i < n; i++) {
if (is_special[i]) {
dist[i] = 0;
root[i] = i;
pq.push({dist[i], i});
}
}
while(!pq.empty()) {
int node = pq.top().second;
int w = pq.top().first;
pq.pop();
if (w != dist[node]) continue;
for (auto to : g[node]) {
if (root[to.first] != -1 && root[to.first] != root[node]) {
pair<int, int> best_way = {dist[node] + to.second + dist[to.first], root[to.first]};
closest_vertex[root[node]] = min(closest_vertex[root[node]], best_way);
}
if (dist[to.first] > dist[node] + to.second) {
dist[to.first] = dist[node] + to.second;
root[to.first] = root[node];
pq.push({dist[to.first], to.first});
}
}
}
int mn = 1e9;
for (int i = 0; i < n; i++) {
if (!is_special[i]) continue;
mn = min(mn, closest_vertex[i].first);
}
add = mn;
if (!basic_graph) {
for (int i = 0; i < n; i++) {
if (!is_special[i]) continue;
if (closest_vertex[i].first == mn) {
res += closest_vertex[i].first;
is_special[i] = false;
is_special[closest_vertex[i].second] = false;
break;
}
}
}
return closest_vertex;
};
if (n > 500) {
Dijkstra(false);
Dijkstra(false);
cout << res << '\n';
} else {
int mn = 1e9;
vector<pair<int, int>> dist = Dijkstra(true);
for (int i = 0; i < n; i++) {
if (!is_special[i]) continue;
if (dist[i].second == -1) continue;
assert(is_special[dist[i].second]);
int cur = dist[i].first;
is_special[i] = false;
is_special[dist[i].second] = false;
add = 0;
Dijkstra(true);
cur += add;
mn = min(mn, cur);
is_special[i] = true;
is_special[dist[i].second] = true;
}
cout << mn << '\n';
}
return 0;
}
