#include <iostream>
#include <fstream>
#include <queue>
#include <vector>
const int inf = 10000000;
using namespace std;
ifstream fin("ubuntzei.in");
ofstream fout("ubuntzei.out");
struct muchie{
    int nod,cost;
};
vector<muchie>v[2500];
int n,m,k,x,y,cost,NOD[1000],sum;
bool ap[1000];
int D[20][2010];
void dijk(int x,int d[])
{
    queue<int>q;
    for(int i=1;i<=n;i++)
        d[i]=inf;
    d[x]=0;
    q.push(x);
    while(!q.empty())
    {
        int nod = q.front();
        q.pop();
        for(auto it:v[nod])
            if(d[it.nod] > d[nod] + it.cost)
            {
                d[it.nod] = d[nod] + it.cost;
                q.push(it.nod);
            }
    }
}
int main() {
    fin>>n>>m>>k;
    for(int i=1;i<=k;i++)
        fin>>NOD[i];
    for(int i=1;i<=m;i++)
    {
        fin>>x>>y>>cost;
        v[x].push_back({y,cost});
        v[y].push_back({x,cost});
    }
    dijk(1, D[0]);
    for(int i=1;i<=k;i++)
        dijk(NOD[i], D[i]);
    int vizitate = 0,ant=0;
    while(vizitate < k)
    {
        int pmin=0,vmin=inf;
        for(int i=1;i<=k;i++)
            if(!ap[i] && D[ant][NOD[i]] < vmin)
            {
                vmin = D[ant][NOD[i]];
                pmin = i;
            }
        sum += vmin;
        ap[pmin]=1;
        vizitate++;
        ant = pmin;
    }
    sum += D[ant][n];
    fout<<sum;
    return 0;
}