#include <bits/stdc++.h>
using namespace std;
const int mxN = 1e5 + 100;
#define int long long
const int inf = 1e18;
vector<pair<int, int>> adj[mxN];
map<int, vector<int>> mp;
int mark[mxN];
void djikstra(int u, int n){
vector<int> dist(n + 1, inf);
priority_queue<pair<int, int>, vector<pair<int, int>>, greater<pair<int, int>>> pq;
dist[u] = 0;
pq.push({0, u});
while(pq.size()){
auto tp = pq.top();
pq.pop();
if(dist[tp.second] < tp.first) continue;
for(auto it : adj[tp.second]){
if(dist[it.first] > tp.first + it.second){
dist[it.first] = tp.first + it.second;
pq.push({dist[it.first], it.first});
}
}
}
mp[u] = dist;
}
signed main(){
ios_base::sync_with_stdio(0);
cin.tie(nullptr); cout.tie(nullptr);
int n, k, m, u, v, w;
cin >> n >> k >> m;
for(int i = 1; i <= k; ++i){
cin >> mark[i];
}
for(int i = 1; i <= m; ++i){
cin >> u >> v >> w;
adj[u].push_back({v, w});
adj[v].push_back({u, w});
}
for(int i = 1; i <= k; ++i){
djikstra(mark[i], n);
}
assert(k <= 3);
if(k == 2){
cout << mp[mark[1]][mark[2]] << "\n";
}else{
int ans = inf;
for(int i = 1; i <= k; ++i){
int middle = mark[i];
int a = 0, b = 0;
if(i == 1) a = mark[2], b = mark[3];
if(i == 2) a = mark[1], b = mark[3];
if(i == 3) a = mark[1], b = mark[2];
ans = min(ans, mp[middle][a] + mp[middle][b]);
}
cout << ans << "\n";
}
return 0;
}
