#include <iostream>
#include <fstream>
#define INF 1000000
#define MAX 2010
using namespace std;
ifstream f ("ubuntzei.in");
ofstream g ("ubuntzei.out");
int a[MAX][MAX],b[MAX][MAX],C[MAX],D[MAX],S[MAX],n,m,k,K,SumMin=INF;
bool FR[MAX];
void Read();
void Dijkstra(int k);
void Back(int k, int sum, int cont);
int main()
{
    Read();
    for (int i=1;i<=k;i++)
        Dijkstra(C[i]);
    // FORMARE MAT CU 1 SI N
    for (int i=1;i<=n;i++)
    {
        S[i]=0;
        b[1][i]=b[i][1];
        b[n][i]=b[i][n];
    }
    Back(1,0,1);
    g<<SumMin;


    /*for (int i=1;i<=n;i++)
    {
        cout<<FR[i]<<"   ";
        for (int j=1;j<=n;j++)
            cout<<b[i][j]<<' ';
        cout<<'\n';
    }*/
    return 0;
}
void Back(int k, int sum, int cont)
{
    S[k]=1;
    if (n==k && cont==K+2&&sum<SumMin) SumMin=sum;
    for (int i=1;i<=n;i++)
        if (FR[i]==true && b[k][i]!=0 && S[i]==0) Back(i,sum+b[k][i], cont+1);
}
void Read()
{
    f>>n>>m>>k;
    K=k;
    for (int i=1;i<=k;i++)
    {
        f>>C[i];
        FR[C[i]]=true;
    }
    FR[1]=FR[n]=true;
    for (int i=1;i<=m;i++)
    {
        int x,y,c;
        f>>x>>y>>c;
        a[x][y]=a[y][x]=c;
    }
}
void Dijkstra(int k)
{
    int u=k;
    for (int i=1;i<=n;i++)
        D[i]=INF,S[i]=0;
    D[k]=0;
    int q=1;
    while (q<=n)
    {
        int Min=INF;
        S[u]=1;
        for (int i=1;i<=n;i++)
            if (a[u][i] && D[i]>a[u][i]+D[u]) D[i] = D[u]+a[u][i];
        for (int i=1;i<=n;i++)
            if (D[i]<Min&&S[i]==0) u=i;
        q++;
    }
    for (int i=1;i<=n;i++)
        b[k][i]=D[i];
}