#include <bits/stdc++.h>
#include <ext/pb_ds/tree_policy.hpp>
#include <ext/pb_ds/assoc_container.hpp>
using namespace std;
using namespace __gnu_pbds;
template<typename T>using ordered_set = tree<T,null_type,less_equal<T>,rb_tree_tag,tree_order_statistics_node_update>;//find_by_order(ind);
//order_of_key()
//#define int long long
#define fast ios_base::sync_with_stdio(0);cin.tie(NULL);cout.tie(NULL);
#define pb push_back
#define yes "YES"
#define no "NO"
#define bigg INT_MAX
#define debug(x) cout<<(#x)<<" = " <<x<<endl;
#define all(x) x.begin(),x.end()
#define sz size()
#define nn '\n'
#define mms(x,y) memset(x,y,sizeof(x))
#define forr(i,j,n) for (int i=j; i<n; i++)
#define forn(i,j,n) for (int i=j; i>n; i--)
#define fi first
#define se second
#define la "LA"
#define cinn(x,y) for(int i=0; i<y; i++) cin>>x[i];
#define pii pair<int,int>
int par[100005];
bool b[100005];
int fin(int x)
{
if (b[par[x]]) return par[x];
return par[x]=fin(x);
}
signed main()
{
// #ifndef LOCAL
// freopen("lifeguards.in","r",stdin);
// freopen("lifeguards.out","w", stdout);
// #endif
fast
int n,m,k;
cin>>n >>m >>k;
vector<pii> a[n+1];
forr(i,0,m)
{
int x,y,z;
cin>>x >>y >>z;
a[x].pb({y,z});
a[y].pb({x,z});
}
int s[k];
priority_queue<array<int,3>> q;
forr(i,0,k)
{
cin>>s[i];
q.push({0,s[i],s[i]});
b[s[i]]=1;
par[s[i]]=s[i];
}
//set <pii>vis;
set<int> vis[n+1];
int ans1=0;
int a1=0, a2=0;
while(!q.empty())
{
int c=q.top()[0], x=q.top()[1], last=q.top()[2];
q.pop();
if (vis[x].find(fin(last))!=vis[x].end()) continue;
par[x]=fin(last);
// cout<<c<<' '<<x<<endl;
if (b[x] && c!=0)
{
// cout<<x<<' '<<c<<endl;
ans1=-c;
a1=x;
a2=par[x];
break;
}
// if (!b[x])
vis[x].insert(par[x]);
// cout<<"PUT"<<x<<' '<<last<<endl;
for(auto y:a[x])
{
// cout"DWAR"<<y.fi<<' '<<par[x]<<endl;
if (vis[y.fi].find(par[x])==vis[y.fi].end() && par[x]!=y.fi)
{
int o=abs(c);
o+=y.se;
q.push({-o,y.fi,par[x]});
// cout<<yes<<y.fi<<' '<<y.se<<' '<<last<<endl;
}
}
}
/////
///new1
while(!q.empty()) q.pop();
// q.clear();
forr(i,1,n+1) vis[i].clear();
mms(par,0);
forr(i,0,k)
{
//cin>>s[i];
if (s[i]==a1 || s[i]==a2) continue;
q.push({0,s[i],s[i]});
// b[s[i]]=1;
par[s[i]]=s[i];
// last[s[i]]=s[i];
}
///////////////
while(!q.empty())
{
int c=q.top()[0], x=q.top()[1], last=q.top()[2];
q.pop();
if (vis[x].find(fin(last))!=vis[x].end()) continue;
par[x]=fin(last);
// cout<<c<<' '<<x<<endl;
if (b[x] && c!=0)
{
// cout<<x<<' '<<c<<endl;
ans1+=(-c);
// a1=x;
// a2=par[x];
break;
}
// if (!b[x])
vis[x].insert(par[x]);
// cout<<"PUT"<<x<<' '<<last<<endl;
for(auto y:a[x])
{
// cout"DWAR"<<y.fi<<' '<<par[x]<<endl;
if (vis[y.fi].find(par[x])==vis[y.fi].end() && par[x]!=y.fi && y.fi!=a1 && y.fi!=a2)
{
int o=abs(c);
o+=y.se;
q.push({-o,y.fi,par[x]});
// cout<<yes<<y.fi<<' '<<y.se<<' '<<last<<endl;
}
}
}
/////////////////
///ans1 done
/////
///new2
while(!q.empty()) q.pop();
// q.clear();
forr(i,1,n+1) vis[i].clear();
mms(par,0);
forr(i,0,k)
{
//cin>>s[i];
if (s[i]==a1) continue;
q.push({0,s[i],s[i]});
// b[s[i]]=1;
par[s[i]]=s[i];
// last[s[i]]=s[i];
}
///////////////
int ans2=0;
int b1=0, b2=0;
while(!q.empty())
{
int c=q.top()[0], x=q.top()[1], last=q.top()[2];
q.pop();
if (vis[x].find(fin(last))!=vis[x].end()) continue;
par[x]=fin(last);
// cout<<c<<' '<<x<<endl;
if (b[x] && c!=0)
{
// cout<<x<<' '<<c<<endl;
ans2=(-c);
b1=x;
b2=par[x];
break;
}
// if (!b[x])
vis[x].insert(par[x]);
// cout<<"PUT"<<x<<' '<<last<<endl;
for(auto y:a[x])
{
// cout"DWAR"<<y.fi<<' '<<par[x]<<endl;
if (vis[y.fi].find(par[x])==vis[y.fi].end() && par[x]!=y.fi && y.fi!=a1)
{
int o=abs(c);
o+=y.se;
q.push({-o,y.fi,par[x]});
// cout<<yes<<y.fi<<' '<<y.se<<' '<<last<<endl;
}
}
}
/////////////////
//new22
while(!q.empty()) q.pop();
// q.clear();
forr(i,1,n+1) vis[i].clear();
mms(par,0);
forr(i,0,k)
{
//cin>>s[i];
if (s[i]==a1) continue;
q.push({0,s[i],s[i]});
// b[s[i]]=1;
par[s[i]]=s[i];
// last[s[i]]=s[i];
}
///////////////
// int ans2=0;
//int b1=0, b2=0;
while(!q.empty()) q.pop();
// q.clear();
forr(i,1,n+1) vis[i].clear();
mms(par,0);
forr(i,0,k)
{
//cin>>s[i];
if (s[i]==b1 || s[i]==b2) continue;
q.push({0,s[i],s[i]});
// b[s[i]]=1;
par[s[i]]=s[i];
// last[s[i]]=s[i];
}
while(!q.empty())
{
int c=q.top()[0], x=q.top()[1], last=q.top()[2];
q.pop();
if (vis[x].find(fin(last))!=vis[x].end()) continue;
par[x]=fin(last);
// cout<<c<<' '<<x<<endl;
if (b[x] && c!=0)
{
// cout<<x<<' '<<c<<endl;
ans2+=(-c);
// b1=x;
// b2=par[x];
break;
}
// if (!b[x])
vis[x].insert(par[x]);
// cout<<"PUT"<<x<<' '<<last<<endl;
for(auto y:a[x])
{
// cout"DWAR"<<y.fi<<' '<<par[x]<<endl;
if (vis[y.fi].find(par[x])==vis[y.fi].end() && par[x]!=y.fi && y.fi!=b1 && y.fi!=b2)
{
int o=abs(c);
o+=y.se;
q.push({-o,y.fi,par[x]});
// cout<<yes<<y.fi<<' '<<y.se<<' '<<last<<endl;
}
}
}
///ans2 done
cout<<min(ans1,ans2);
return 0;
}
