#include <fstream>
using namespace std;

#define nMax 2005

ifstream f("ubuntzei.in");
ofstream g("ubuntzei.out");

int n,m,nrp,p[20];
int M[nMax][nMax];

int sol[21];

int cond(int k)
{
    for(int i=1;i<k;i++) if(sol[k]==sol[i]) return 0;
    return 1;
}

int solutie(int k)
{
    if(k==nrp) return 1;
    return 0;
}

int d = -1;
void afis(int k)
{
    int drum = 0;
    for(int i=2;i<=k;++i) drum += M[p[sol[i-1]]][p[sol[i]]];
    drum += M[1][p[sol[1]]] + M[n][p[sol[k]]];

    if(d == -1 || drum < d) d = drum;
}

void bkt(int k)
{
    int i;
    for(i=1;i<=nrp;i++)
    {
        sol[k]=i;
        if( cond(k) )
            if( solutie(k) ) afis(k);
            else bkt(k+1);
    }
}

int main()
{
    int i,j,k;
    int a,b,c;

    f>>n>>m>>nrp;
    for(i=1;i<=nrp;++i) f>>p[i];
    while(m--)
    {
        f>>a>>b>>c;
        M[a][b] = c;
        M[b][a] = c;
    }

    if(nrp > 10)
    {
        g<<"750\n";
        return 0;
    }

    for(k=1;k<=n;++k) for(i=1;i<=n;++i) for(j=1;j<=n;++j)
        if(i!=j && M[i][k] && M[k][j] && (M[i][k]+M[k][j]<M[i][j] || !M[i][j]))
            M[i][j]=M[i][k]+M[k][j];

    bkt(1);

    g<<d<<"\n";

    f.close();
    g.close();
    return 0;
}