#include <iostream>
#include <vector>
#include <cmath>
#include <algorithm>
#include <string>
#include <map>
#include <unordered_map>
#include <set>
#include <unordered_set>
#include <queue>
#include <deque>
#include <list>
using namespace std;
typedef long long int ll;
typedef unsigned long long int ull;
typedef long double ld;
#define REP(i,a,b) for(ll i=a; i<b; i++)
#define pb push_back
#define mp make_pair
#define pl pair<ll,ll>
#define ff first
#define ss second
#define whole(x) x.begin(),x.end()
#define DEBUG(i) cout<<"Pedro Is The Master "<<i<<endl
#define INF 100000000000000000LL
ll insig;
#define In(vecBRO, LENBRO) REP(IBRO,0,LENBRO) {cin>>insig; vecBRO.pb(insig);}
void Out(vector<ll> x) {REP(i,0,x.size()) {cout<<x[i]<<" ";} cout<<endl;}
class WG //everything works for weighted directed graphs
{
public:
ll N; vector<vector<pl> > adj;
vector<bool> pr; vector<ll> nv;
WG(vector<vector<pl> > ad)
{
adj=ad; N=adj.size();
REP(i,0,N) {pr.pb(false); nv.pb(0);}
}
void Reset()
{
REP(i,0,N) {pr[i]=false;nv.pb(0);}
}
vector<ll> Djikstra(ll s)
{
Reset();
vector<ll> d; REP(i,0,N) {d.pb(INF);}
d[s]=0;
priority_queue<pl> q;
q.push(mp(0,s));
ll cur;
while(!q.empty())
{
cur=q.top().ss; q.pop();
if(pr[cur]) {continue;}
pr[cur]=true;
REP(i,0,adj[cur].size())
{
if(d[adj[cur][i].ff]>d[cur]+adj[cur][i].ss)
{
d[adj[cur][i].ff]=d[cur]+adj[cur][i].ss;
q.push(mp(-d[adj[cur][i].ff],adj[cur][i].ff));
}
}
}
return d;
}
vector<pl> Djikstra_MS(vector<ll> sn) //Djikstra Multi-sourced, ans[i].ff=d(i,sn), ans[i].ss=member of sn closest to i
{
Reset();
ll K=sn.size();
vector<pl> d; REP(i,0,N) {d.pb(mp(INF,-1LL));}
REP(i,0,K) {d[sn[i]]=mp(0LL,sn[i]);}
priority_queue<pl> q;
REP(i,0,K) {q.push(mp(0,sn[i]));}
ll cur;
while(!q.empty())
{
cur=q.top().ss; q.pop();
if(pr[cur]) {continue;}
pr[cur]=true;
REP(i,0,adj[cur].size())
{
if(d[adj[cur][i].ff].ff>d[cur].ff+adj[cur][i].ss)
{
d[adj[cur][i].ff].ff=d[cur].ff+adj[cur][i].ss;
d[adj[cur][i].ff].ss=d[cur].ss;
q.push(mp(-d[adj[cur][i].ff].ff,adj[cur][i].ff));
}
}
}
return d;
}
};
int main()
{
ios_base::sync_with_stdio(0);
cin.tie(0); cout.tie(0);
ll N,M,K; cin>>N>>M>>K; vector<ll> A; vector<pl> xx; vector<vector<pl> > adj; REP(i,0,N) {adj.pb(xx);}
pl cur; ll we;
REP(i,0,M) {cin>>cur.ff>>cur.ss>>we; cur.ff--; cur.ss--; adj[cur.ff].pb(mp(cur.ss,we)); adj[cur.ss].pb(mp(cur.ff,we));}
WG G(adj);
In(A,K); REP(i,0,K) {A[i]--;}
ll ans=INF; pl co; ll sp=INF;
vector<pl> d=G.Djikstra_MS(A);
REP(i,0,N)
{
REP(j,0,adj[i].size())
{
if(d[i].ss==d[adj[i][j].ff].ss) {continue;}
if(d[i].ff+d[adj[i][j].ff].ff+adj[i][j].ss<sp)
{
sp=d[i].ff+d[adj[i][j].ff].ff+adj[i][j].ss;
co=mp(d[i].ss,d[adj[i][j].ff].ss);
}
}
}
ans=sp;
sp=INF;
pl co2;
A.erase(find(whole(A),co.ff));
A.erase(find(whole(A),co.ss));
d=G.Djikstra_MS(A);
REP(i,0,N)
{
REP(j,0,adj[i].size())
{
if(i==co.ff || i==co.ss || adj[i][j].ff==co.ff || adj[i][j].ff==co.ss) {continue;}
if(d[i].ss==d[adj[i][j].ff].ss) {continue;}
if(d[i].ff+d[adj[i][j].ff].ff+adj[i][j].ss<sp)
{
sp=d[i].ff+d[adj[i][j].ff].ff+adj[i][j].ss;
co2=mp(d[i].ss,d[adj[i][j].ff].ss);
}
}
}
ans+=sp;
vector<ll> d1=G.Djikstra(co.ff);
vector<ll> d2=G.Djikstra(co.ss);
ll mindist1=INF; ll par1; ll mindist2=INF; ll par2;
REP(j,0,K)
{
ll i=A[j];
if(i==co.ff || i==co.ss) {continue;}
if(d1[i]<mindist1) {mindist1=d1[i]; par1=i;}
}
REP(j,0,K)
{
ll i=A[j];
if(i==co.ff || i==co.ss || i==par1) {continue;}
if(d2[i]<mindist2) {mindist2=d2[i]; par2=i;}
}
ans=min(ans,mindist1+mindist2);
mindist1=INF; mindist2=INF;
REP(j,0,K)
{
ll i=A[j];
if(i==co.ff || i==co.ss) {continue;}
if(d2[i]<mindist2) {mindist2=d2[i]; par2=i;}
}
REP(j,0,K)
{
ll i=A[j];
if(i==co.ff || i==co.ss || i==par2) {continue;}
if(d1[i]<mindist1) {mindist1=d1[i]; par1=i;}
}
ans=min(ans,mindist1+mindist2);
cout<<ans<<endl;
return 0;
}
