#include <iostream>
#include <fstream>
#include <bitset>
using namespace std;
ifstream f("ubuntzei.in");
ofstream g("ubuntzei.out");
int start[2001],t[3][20002],n,m,coada[400004],c[2001],orase[20];
bitset <2001>viz;

void initializare()
{
    int i;
    for(i=1;i<=n;i++)
    {
        c[i]=10000001;
        viz[i]=0;
    }
}

void ford(int nod)
{
    int prim,ultim,x,p;
    c[nod]=0;
    prim=ultim=1;
    coada[prim]=nod;
    while(prim<=ultim)
    {
        x=coada[prim];
        p=start[x];
        viz[x]=0;
        while(p)
        {
            if(c[x]+t[2][p]<c[t[0][p]])
            {
                c[t[0][p]]=c[x]+t[2][p];
                if(viz[t[0][p]]==0)
                {
                    coada[++ultim]=t[0][p];
                    viz[t[0][p]]=1;
                }
            }
            p=t[1][p];
        }
        prim++;
    }
}
int main()
{
    int o,i,j,k=0,cost,z;
    int distanta=0,ant;
    f>>n>>m;
    f>>z;
    for(o=1;o<=z;o++) f>>orase[o];
    for(o=1;o<=m;o++)
    {
        f>>i>>j>>cost;
        k++;
        t[0][k]=j;
        t[1][k]=start[i];
        start[i]=k;
        t[2][k]=cost;
        k++;
        t[0][k]=i;
        t[1][k]=start[j];
        start[j]=k;
        t[2][k]=cost;
    }
    ant=1;
    for(o=1;o<=z;o++)
    {
       initializare();
       ford(ant);
       distanta+=c[orase[o]];
       ant=orase[o];
    }
    initializare();
    ford(orase[z]);
    distanta+=c[n];
    g<<distanta;
    return 0;
}