#include <bits/stdc++.h>
#define int long long
using namespace std;
const int O = 3e6 + 5;
const int inf = 1e18;
int n, k, m, E[O], W[O], par[O];
vector <int> g[O];
priority_queue <pair <int, int>, vector <pair <int, int>>, greater <pair <int, int>>> q;
vector <int> Dijktra(vector <int> S){
vector <int> d(n);
for (int i = 0; i < n; ++ i) d[i] = inf, par[i] = 0;
for (int i : S){
d[i] = 0;
par[i] = i;
q.push({0, i});
}
while (q.size()){
int u = q.top().second;
int dist = q.top().first;
q.pop();
if (dist != d[u]) continue;
for (int i : g[u]){
int v = u ^ E[i];
int w = W[i];
if (dist + w < d[v]){
d[v] = dist + w;
par[v] = par[u];
q.push({dist + w, v});
}
}
}
return d;
}
array <int, 3> bestPair(vector <int> d){
array <int, 3> res; res[2] = inf;
for (int u = 0; u < n; ++ u){
for (int i : g[u]){
int v = u ^ E[i];
int w = W[i];
if (par[u] != par[v] && d[u] + d[v] + w < res[2]){
res[0] = par[u];
res[1] = par[v];
res[2] = d[u] + d[v] + w;
}
}
}
return res;
}
main(){
ios_base::sync_with_stdio(false); cin.tie(0); cout.tie(0);
cin >> n >> m >> k;
for (int i = 1; i <= m; ++ i){
int u, v, w; cin >> u >> v >> w;
u -= 1; v -= 1;
g[u].push_back(i);
g[v].push_back(i);
E[i] = u ^ v;
W[i] = w;
}
vector <int> specials(k);
for (auto &i : specials){
cin >> i; i -= 1;
}
///
array <int, 3> P1 = bestPair(Dijktra(specials));
vector <int> anoSpecials;
for (int i : specials){
if (i != P1[0] && i != P1[1]){
anoSpecials.push_back(i);
}
}
array <int, 3> P2 = bestPair(Dijktra(anoSpecials));
///
int res = P1[2] + P2[2];
vector <int> onlyP0 = {P1[0]};
vector <int> onlyP1 = {P1[1]};
vector <int> dist0 = Dijktra(onlyP0);
vector <int> dist1 = Dijktra(onlyP1);
set <pair <int, int>> Min;
for (int i : specials){
if (i != P1[0] && i != P1[1]){
Min.insert({dist1[i], i});
}
}
for (int i : specials){
if (i != P1[0] && i != P1[1]){
Min.erase({dist1[i], i});
int minCost = (*Min.begin()).first;
Min.insert({dist1[i], i});
res = min(res, dist0[i] + minCost);
}
}
cout << res;
}
