#include<fstream>
#define inf 1<<30
using namespace std;
ifstream f("ubuntzei.in");
ofstream g("ubuntzei.out");
int n,m,i,k,d[2005],xx,j,fin,nod,poz,val;
struct localitati
{
    int x,y,c;
}a[20005];
bool viz[2005],ok;
void dijkstra()
{
    for(i=1;i<=n;i++)
      d[i]=inf;
    d[nod]=0;
    for(i=1;i<=m;i++)
      if(a[i].x==nod)
        d[a[i].y]=a[i].c;
    do
    {
        ok=1;
        for(i=1;i<=m;i++)
          if(d[a[i].y]>d[a[i].x]+a[i].c)
          {
              d[a[i].y]=d[a[i].x]+a[i].c;
              ok=0;
          }
    }while(ok==0);
    poz=0;
    val=inf;
    for(i=1;i<=n;i++)
      if(viz[i]==1)
      {
          if(d[i]<val)
          {
              poz=i;
              val=d[i];
          }
      }
    if(poz!=0)
    {
        viz[poz]=0;
        nod=poz;
        fin+=val;
    }
    else
    {
        nod=n;
        fin+=d[n];
    }
}
int main()
{
    f>>n>>m;
    f>>k;
    for(int i=1;i<=k;i++)
    {
        f>>xx;
        viz[xx]=1;
    }
    for(int i=1;i<=m;i++)
    {
        f>>a[i].x>>a[i].y>>a[i].c;
        a[i+m].y=a[i].x;
        a[i+m].x=a[i].y;
        a[i+m].c=a[i].c;
    }
    m*=2;
    nod=1;
    while(nod!=n)
      dijkstra();
    g<<fin;
    return 0;
}