#include <bits/stdc++.h>
using namespace std;

ifstream f("ubuntzei.in");
ofstream g("ubuntzei.out");

int n,m;
bool town[2005];
vector < pair < int , int > > v[2005];
int k;
int tn,x,y,c;
int dp[2005][16];
int oo=2000000009;
set < pair < pair < int , int > , pair < int , int > > > s;

int main()
{
    f >> n >> m;
    f >> k;
    for (int i=1;i<=k;i++) {
        f >> tn;
        town[tn]=1;
    }
    for (int i=1;i<=m;i++) {
        f >> x >> y >> c;
        v[x].push_back({y,c});
        v[y].push_back({x,c});
    }
    for (int i=1;i<=n;i++) {
        for (int j=0;j<=k;j++) {
            dp[i][j]=oo;
        }
    }
    dp[1][0]=0;
    s.insert({{0,0},{1,0}});
    while (s.empty()==0) {
        int nod = s.begin()->second.first;
        int nrviz = s.begin()->second.second;
        s.erase(s.begin());
        for (int i=0;i<v[nod].size();i++) {
            int nodtoviz = v[nod][i].first;
            int distance = v[nod][i].second;
            int istown = town[nodtoviz];
            if (dp[nodtoviz][nrviz+istown] > dp[nod][nrviz] + distance) {
                s.erase({{dp[nodtoviz][nrviz+istown],0},{nodtoviz,nrviz+istown}});
                dp[nodtoviz][nrviz+istown] = dp[nod][nrviz] + distance;
                s.insert({{dp[nodtoviz][nrviz+istown],0},{nodtoviz,nrviz+istown}});
            }
        }
    }
    g << dp[n][k];
    return 0;
}