#include <cstdio>
#include <vector>
#include <algorithm>
#include <set>
#include <cstring>

#define NMax 2005
#define INF 0x3f3f3f3f
using namespace std;

vector<pair<int,int> > vecini[NMax];
int n,m,x,y,c,k;
int a[NMax];

void dijkstra(int x0){
    int dist[NMax],viz[NMax];
    set<pair<int,int> > H;

    memset(dist,INF,sizeof(dist));
    memset(viz,0,sizeof(viz));

    dist[x0] = 0;
    H.insert(make_pair(0,x0));

    while(!H.empty()){
        int nod = (*H.begin()).second;
        H.erase(*H.begin());

        for(int i = 0; i < vecini[nod].size(); i++){
            if(dist[vecini[nod][i].first] > dist[nod] + vecini[nod][i].second){
                dist[vecini[nod][i].first] = dist[nod] + vecini[nod][i].second;
                H.insert(make_pair(dist[vecini[nod][i].first], vecini[nod][i].first));
            }
        }
    }
    printf("%d",dist[n]);
}
int main()
{
    freopen("ubuntzei.in","r",stdin);
    freopen("ubuntzei.out","w",stdout);
    scanf("%d%d",&n,&m);
    scanf("%d",&k);
    for(int i = 1; i <= k; i++){
        scanf("%d",&a[i]);
    }
    for(int i = 1; i <= m; i++){
        scanf("%d%d%d",&x,&y,&c);
        vecini[x].push_back(make_pair(y,c));
        vecini[y].push_back(make_pair(x,c));
    }
    dijkstra(1);
    return 0;
}