#include <iostream>
#include <fstream>
#include <vector>
#include <queue>

using namespace std;
ifstream fin("ubuntzei.in");
ofstream fout("ubuntzei.out");


int n, m, k, v[20], x, y, z, d[2001], f[2001];
int cost;
struct compara
{
    bool operator () (int x, int y)
    {return d[x]>d[y];
    }
};

vector <pair <int, int> > g[2001];
priority_queue <int, vector <int>, compara> q;


void dijkstra (int s)
{int i, k, vecin, cost;
for(i=1; i<=n; i++)
    d[i]=1000000000, f[i]=0;
d[s]=0;
q.push(s);
f[s]=1;

while(!q.empty())
{k=q.top();
q.pop();
f[k]=0;
for(i=0; i<g[k].size(); i++)
{vecin=g[k][i].first;
cost=g[k][i].second;
if(d[vecin]>d[k]+cost)
{d[vecin]=d[k]+cost;
if(f[vecin]==0)
{q.push(vecin);
f[vecin]=1;
}
}
}
}

}

int main()
{int i, j;
fin>>n>>m;
fin>>k;
for(i=1; i<=k; i++)
    fin>>v[i];
for(i=1; i<=m; i++)
{fin>>x>>y>>z;
g[x].push_back(make_pair(y, z));
g[y].push_back(make_pair(x, z));
}

dijkstra(1);
for(i=1; i<=k; i++)
{cost+=d[v[i]];
dijkstra[v[i]];
}
cost+=d[n];
fout<<cost;

    return 0;
}