#include <iostream>
#include <fstream>
#include <bits/stdc++.h>
#include <bitset>
#define pb push_back
#define NM 2005
using namespace std;
ifstream in("ubuntei.in");
ofstream out("ubuntei.out");
///bitset<(1<<15)+5> b[NM];
struct eee
{
    int nod,cost,config;
    bool operator < (const eee &a) const
    {
        return cost>a.cost;
    }
};
priority_queue<eee> q;
vector<eee> v[NM];
int n,m,dmin[NM],c[NM],k,x,y,z;
int main()
{
    in>>n>>m>>k;
    for(int i=0;i<k;++i)
    {
        in>>x;
        c[x]=(1<<i);
    }
    for(int i=1;i<=m;++i)
    {
        in>>x>>y>>z;
        v[x].pb({y,z,0});
        v[y].pb({x,z,0});
    }
    q.push({1,0,0});
    while(q.top().nod!=n || q.top().config!=((1<<k)-1))
    {
        int nod=q.top().nod,cost=q.top().cost,config=q.top().config;
        q.pop();
        for(auto s:v[nod])
        {
            ///if(c[s.nod] && config!=(config|c[s.nod]) && cost+s.cost<dmin[s.nod][config|c[s.nod]])
              ///  dmin[s.nod][config|c[s.nod]]=s.cost+cost;
            q.push({s.nod,cost+s.cost,config|c[s.nod]});
        }
    }
    out<<q.top().cost;
    return 0;
}