#include<bits/stdc++.h>
using namespace std;
typedef pair<int,int> pii;
typedef pair<int,pii> piii;
const int MAXN=1e5+5,INF=1e9;
vector<pii> adj[MAXN];
int head[MAXN],dist[MAXN],n;
bool special[MAXN],skip[MAXN];
piii MinimumPairSpecialDistance(){
priority_queue<pii,vector<pii>,greater<pii>> PQ;
for(int i=1;i<=n;i++)dist[i]=INF;
for(int i=1;i<=n;i++){
if(!special[i] || skip[i])continue;
dist[i]=0;
head[i]=i;
PQ.push({dist[i],i});
}
while(!PQ.empty()){
pii now=PQ.top();
PQ.pop();
if(dist[now.second]<now.first)continue;
for(auto nxt : adj[now.second]){
if(!skip[nxt.first] && dist[now.second]+nxt.second<dist[nxt.first]){
dist[nxt.first]=dist[now.second]+nxt.second;
head[nxt.first]=head[now.second];
PQ.push({dist[nxt.first],nxt.first});
}
}
}
int val=INF;
pii ret;
for(int i=1;i<=n;i++){
for(auto j : adj[i]){
if(head[i]==head[j.first] || skip[head[i]] || skip[head[j.first]])continue;
if(dist[i]+j.second+dist[j.first]<val){
val=dist[i]+j.second+dist[j.first];
ret={head[i],head[j.first]};
}
}
}
return {val,ret};
}
int kasusdua(int a,int b){
priority_queue<pii,vector<pii>,greater<pii>> PQ;
for(int i=1;i<=n;i++)dist[i]=INF;
dist[a]=0;
PQ.push({dist[a],a});
while(!PQ.empty()){
pii now=PQ.top();
PQ.pop();
if(dist[now.second]<now.first)continue;
for(auto nxt : adj[now.second]){
if(dist[now.second]+nxt.second<dist[nxt.first]){
dist[nxt.first]=dist[now.second]+nxt.second;
PQ.push({dist[nxt.first],nxt.first});
}
}
}
vector<pii> jaraka;
for(int i=1;i<=n;i++){
if(i==a || i==b || !special[i])continue;
jaraka.push_back({dist[i],i});
}
sort(jaraka.begin(),jaraka.end());
for(int i=1;i<=n;i++)dist[i]=INF;
dist[b]=0;
PQ.push({dist[b],b});
while(!PQ.empty()){
pii now=PQ.top();
PQ.pop();
if(dist[now.second]<now.first)continue;
for(auto nxt : adj[now.second]){
if(dist[now.second]+nxt.second<dist[nxt.first]){
dist[nxt.first]=dist[now.second]+nxt.second;
PQ.push({dist[nxt.first],nxt.first});
}
}
}
vector<pii> jarakb;
for(int i=1;i<=n;i++){
if(i==a || i==b || !special[i])continue;
jarakb.push_back({dist[i],i});
}
sort(jarakb.begin(),jarakb.end());
if(jaraka[0].second==jarakb[0].second)return min(jaraka[0].first+jarakb[1].first,jaraka[1].first+jarakb[0].first);
else return jaraka[0].first+jarakb[0].first;
}
int main(){
ios_base::sync_with_stdio(false);cin.tie(NULL);cout.tie(NULL);
int m,k,u,v,w;
cin >> n >> m >> k;
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++){
cin >> u;
special[u]=true;
}
piii temp=MinimumPairSpecialDistance();
int kasussatu=temp.first,a=temp.second.first,b=temp.second.second;
skip[a]=true;skip[b]=true;
kasussatu+=MinimumPairSpecialDistance().first;
int ans=kasussatu;
ans=min(ans,kasusdua(a,b));
cout << ans << '\n';
return 0;
}
