#include <bits/stdc++.h>
//#include "bits_stdc++.h"
#define f first
#define s second
#define mp make_pair
#define pb push_back
#define lb lower_bound
#define ub upper_bound
#define show(x) cerr << #x << " is " << x << endl;
#define show2(x,y) cerr << #x << " is " << x << " " << #y << " is " << y << endl;
#define show3(x,y,z) cerr << #x << " is " << x << " " << #y << " is " << y << " " << #z << " is " << z << endl;
using namespace std;
typedef long long ll;
typedef pair<ll, ll> pi;
ll n, m, k;
ll ans = LLONG_MAX;
vector<pi> adj[100005];
bool special[100005], skip[100005];
vector<ll> dist;
ll par[100005];
ll b1, b2, distan;
void findclosestpair()
{
b1= -1, b2=-1;
distan = LLONG_MAX;
priority_queue<pi, vector<pi>, greater<pi> > pq;
dist.assign(n+1, LLONG_MAX);
for (ll i=1; i<=n; ++i)
{
if (!special[i] || skip[i]) continue;
dist[i] = 0;
pq.push(mp(dist[i], i));
par[i] = i;
}
while (!pq.empty())
{
pi temp = pq.top();
ll from = temp.second;
pq.pop();
//if (dist[from]< temp.f) continue;
for (pi u: adj[from])
{
if (!skip[u.f] && dist[u.f]>dist[from]+u.s)
{
dist[u.f] = dist[from] + u.s;
par[u.f] = par[from];
pq.push(mp(dist[u.f], u.f));
}
}
}
for (ll i=1; i<=n; ++i)
{
if (skip[par[i]]) continue;
for(pi u: adj[i])
{
if (par[u.f]==par[i] || skip[par[u.f]]) continue;
if (dist[i] + u.s + dist[u.f] < distan)
{
distan = dist[i] + u.s + dist[u.f];
b1 = par[i], b2 = par[u.f];
}
}
}
}
vector<ll> dijkstra(ll src)
{
priority_queue<pi, vector<pi>, greater<pi> > pq;
vector<ll> dist(n+1, LLONG_MAX);
dist[src] = 0;
pq.push(mp(0, src));
while (!pq.empty())
{
ll from = pq.top().second;
pq.pop();
for (pi u: adj[from])
{
if (dist[u.f]>dist[from]+u.s)
{
dist[u.f] = dist[from] + u.s;
pq.push(mp(dist[u.f], u.f));
}
}
}
return dist;
}
int main()
{
cin >> n >> m >> k;
for (ll i=0; i<m; ++i)
{
ll a,b,c;
cin >> a >> b >> c;
adj[a].pb(mp(b,c));
adj[b].pb(mp(a,c));
}
for (ll i=1; i<=k; ++i)
{
ll a;
cin >> a;
special[a] = 1;
}
//cout << "done" << endl;
// find x1, x2 (closest pair)
findclosestpair();
// case 1: join (x1, x2) -> find another paur
ll add = distan;
ll a = b1, b = b2;
//cout << a << b << endl;
skip[a] = 1, skip[b] = 1;
findclosestpair();
ans = add+ distan;
//cout << "done" << endl;
//cout << ans << endl;
// case 2: seperate x1 from x2 -> pair both up
vector<ll> fromb1 = dijkstra(a), fromb2 = dijkstra(b);
vector<pi> choose1, choose2;
for (ll i=1; i<=n; ++i)
{
if (i==a || i==b || !special[i]) continue;
choose1.pb(mp(fromb1[i], i));
choose2.pb(mp(fromb2[i], i));
}
//cout << "done" << endl;
sort(choose1.begin(), choose1.end());
sort(choose2.begin(), choose2.end());
if (choose1[0].s == choose2[0].s)
{
//cout << "one" << endl;
//cout << choose1[0].s << endl;
if (choose1[1].f!=LLONG_MAX && choose2[0].f!=LLONG_MAX) ans = min(ans, choose1[1].f + choose2[0].f);
if (choose2[1].f!=LLONG_MAX && choose1[0].f!=LLONG_MAX) ans = min(ans, choose2[1].f + choose1[0].f);
}
else
{
if (choose1[0].f!=LLONG_MAX && choose2[0].f!=LLONG_MAX) ans = min(ans, choose1[0].f + choose2[0].f);
//cout << choose1[0].f << ' ' << choose2[0].f << endl;
}
cout << ans << endl;
return 0;
}
