#include <cstdio>
#include <vector>
#include <queue>
#include <cstring>
#include <iostream>
using namespace std;

const int inf = 0x3f3f3f3f;
const int nmx = 2002;
const int kmx = 16;

int n,m,k,l[kmx][nmx],dp[kmx][nmx],oras[kmx];
vector <pair<int,int> > g[nmx];
priority_queue <pair<int,int> > q;

void citire() {
    scanf("%d %d", &n, &m);
    scanf("%d", &k);

    for(int i = 1; i <= k; ++i)
        scanf("%d", &oras[i]);

    int nod1, nod2, cost;
    for(int i = 1; i <= m; ++i) {
        scanf("%d %d %d", &nod1, &nod2, &cost);
        g[nod1].push_back(make_pair(nod2,cost));
        g[nod2].push_back(make_pair(nod1,cost));
    }
}

void dijkstra(int nr_oras, int nod_start) { /// l[i][j] distanta de la orasul i la nodul j
    l[nr_oras][nod_start] = 0;
    q.push(make_pair(0,nod_start));
    while(not q.empty()){
        int nod = q.top().second;
        q.pop();
        for(vector<pair<int,int> >::iterator it = g[nod].begin(); it != g[nod].end(); ++it)
        if(l[nr_oras][it->first] > l[nr_oras][nod] + it->second){
            l[nr_oras][it->first] = l[nr_oras][nod] + it->second;
            q.push(make_pair(-l[nr_oras][it->first],it->first));
        }
    }
}

void dinamica(){ /// dp[i][j] costul ptr drumul min format din i orase pana in orasul j
    memset(dp,inf,sizeof(dp));
    for(int i = 1; i <= k; ++i)
        dp[0][i] = l[0][oras[i]];
    dp[0][0] = 0;
    for(int t = 1; t <= k; ++t)
        for(int p = 1; p <= k; ++p)
            for(int j = 0; j <= k; ++j)
                if(p != j)
                     dp[t][p] = min(dp[t][p],dp[t-1][j] + l[j][oras[p]]);

    int miin = inf;
    for(int i = 1; i <= k; ++i)
        if(miin > dp[k][i] + l[i][n])
            miin = dp[k][i] + l[i][n];
    printf("%d\n", miin);
}

int main() {
    freopen("ubuntzei.in", "r", stdin);
    freopen("ubuntzei.out", "w", stdout);
    citire();
    memset(l,inf,sizeof(l));
    oras[0] = 1;
    for(int i = 0; i <= k; ++i)
        dijkstra(i,oras[i]);

    dinamica();
    return 0;
}