#include <iostream>
#include <fstream>
#include <vector>
#include <queue>
using namespace std;

ifstream fin("ubuntzei.in");
ofstream fout("ubuntzei.out");

int n,m,k;
int P[2001];
int DIST[2001][65537];
bool viz[2001][65537];
vector <pair<int,int> > V[2001];
priority_queue < pair < int, pair < int, int > > > Q;
int main()
{
    fin>>n>>m;
    fin>>k;
    for(int i=1;i<=k;i++)
    {
        int x;
        fin>>x;
        P[x]=i;
    }
    for(int i=1;i<=m;i++)
    {
        int a,b,c;
        fin>>a>>b>>c;
        V[a].push_back({-1*c,b});
    }
    for(int i=1;i<=n;i++)
        for(int j=1;j<=(1<<(k+1));j++)
            DIST[i][j]=-1000000000;
    Q.push({0,{1,0}});
    while(!Q.empty())
    {
        int dnod=Q.top().first;
        int nod=Q.top().second.first;
        int mascapriet=Q.top().second.second;
        Q.pop();
        for(auto it:V[nod])
        {
            int ndnod=it.first;
            int nnod=it.second;
            int adg=0;
            if(P[nnod]!=0)
                adg=mascapriet+(1<<(P[nnod]-1));
            if(DIST[nod][mascapriet]+ndnod>=DIST[nnod][mascapriet+adg])
            {
                DIST[nnod][mascapriet+adg]=DIST[nod][mascapriet]+ndnod;
                Q.push({DIST[nnod][mascapriet+adg],{nnod,(mascapriet+adg)}});
            }
        }
    }
    fout<<-DIST[n][(1<<(k))-1];
    return 0;
}