#include<stdio.h>
#include<vector>
#include<queue>
#include<fstream>
using namespace std;

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

typedef vector<pair<int,int> >::iterator it;

#define MaxN 2010
#define MaxK 21

int N,M,K,MAX = 2139123,T[MaxK] = {1},D[MaxK][MaxN],V[MaxK],viz[MaxK];
bool isCoada[MaxN];
vector<pair<int,int> > A[MaxN];

void citire(void)
{
	int a,b,c;
	
	f >> N >> M;
	
	f >> K;
	for(int i=1;i<=K;i++)
		f >> T[i];
	
	for(int i=1;i<=M;i++)
	{
		f >> a >> b >> c;
		A[a].push_back(make_pair(b,c));
		A[b].push_back(make_pair(a,c));
	}
}

void BellmanFord(int k)
{
	queue<int> Q;
	
	for(Q.push(T[k]);!Q.empty();isCoada[Q.front()] = false,Q.pop())
		for(it i=A[Q.front()].begin();i<A[Q.front()].end();i++)
			if(!D[k][i->first] || D[k][i->first] > D[k][Q.front()] + i->second)
			{
				D[k][i->first] = D[k][Q.front()]+i->second;
				if(!isCoada[i->first])
					Q.push(i->first),isCoada[i->first] = true;
			}
			
	D[k][T[k]] = 0;
}

void BellmanFordPentruToate(void)
{	
	for(int i=0;i<=K;i++)
		BellmanFord(i);
}

inline void back(int k,int S)
{
	if(k == K+1)
	{
		if(S+D[V[k-1]][N] < MAX)
			MAX = S+D[V[k-1]][N];
		
		return ;
	}
	
	for(int i=1;i<=K;i++)
		if(!viz[i] && S+D[V[k-1]][T[i]] < MAX)
		{
			V[k] = i;
			viz[i] = 1;
			back(k+1,S+D[V[k-1]][T[i]]);
			viz[i] = 0;
		}
}

void AflaMinimul(void)
{
	BellmanFordPentruToate();
	
	back(1,0);
}

int main()
{
	citire();
	AflaMinimul();
	
	g << MAX;
	
	return 0;
}