#include <fstream>
#define Nmax 2099
#define Mmax 10099
#define Kmax 20
#define Inf 999999999
using namespace std;
ifstream f("ubuntzei.in");
ofstream g("ubuntzei.out");

int N,M,K,P[Kmax],st[Kmax],used[Kmax],sol;
struct muchie{int x,y,c;}Much[Mmax];

inline void ReadInput()
{
    f>>N>>M>>K;
    for(int i=1;i<=K;++i)f>>P[i];
    for(int i=1;i<=M;++i)
    {
        int x,y,cost;
        f>>x>>y>>cost;
        Much[i].x=x , Much[i].y=y, Much[i].c=cost;
    }
}

void Dijkstra(muchie a[Mmax],int M)
{
    int d[Nmax];
    int start=1;
    for(int i=1;i<=N+10;++i)d[i]=Inf;
    for(int i=1;i<=M;++i)
        if(a[i].x==start) d[a[i].y]=a[i].c;
        else if(a[i].y==start) d[a[i].x]=a[i].c;
    int gata=0;
    while(!gata)
    {
        gata=1;
        for(int i=1; i<=M;++i)
            if(d[a[i].y]>d[a[i].x]+a[i].c)
            {
                gata=0;
                d[a[i].y]=d[a[i].x]+a[i].c;
            }
            else
            if(d[a[i].x]>d[a[i].y]+a[i].c)
            {
                gata=0;
                d[a[i].x]=d[a[i].y]+a[i].c;
            }
    }
    if(d[N]<sol)sol=d[N];
}
void Print(int vf)
{
    for(int i=1;i<vf;++i)g<<st[i]<<' ';g<<'\n';
}
void Back(int k)
{
    if(k>1)Print(k);
    if(k>K+1-st[1])return;
    for(int i=st[k-1]+1;i<=K;++i)
        {
            st[k]=i;
            Back(k+1);
        }
}

int main()
{
    ReadInput();
    sol=Inf;
    if(!K)Dijkstra(Much,M);
    else Back(1);
    g<<sol<<'\n';
    f.close();g.close();
    return 0;
}