#include <iostream>
#include <fstream>
#include <vector>
#include <queue>
#include <tuple>
using namespace std;
using PI = pair<int, int>;
using VI = vector<int>;
using VPI = vector<PI>;
using VVI = vector<VI>;
using VVPI = vector<VPI>;
using VB = vector<bool>;

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

struct Cell {
	int x, w;
	
	Cell(int x = 0, int w = 0) : x {x}, w {w}
	{}
	
	bool operator < (Cell const& other) const noexcept
	{
		return w > other.w;
	}
};

const int INF = 0x3f3f3f3f;
int n, m, k;
VI nodes, d;
VB v;
VVPI adj;

void ReadInput();
void Dijsktra(int x, VI& d);

int main()
{
	ReadInput();
	
	int currNode(1), ans(0);
	
	while (true)
	{
		if (currNode == n)
			break;
	
		Dijsktra(currNode, d);
		
		int minDist(INF), nextNode;
		for (int i = 1; i <= k; ++i)
		{
			if (v[i])
				continue;
				
			if (d[i] < minDist)
			{
				minDist = d[i];
				nextNode = nodes[i];
			}
		} 
		
		ans += d[nextNode];
		currNode = nextNode;
	}
	
	fout << ans;
	
	return 0;
}

void Dijsktra(int x, VI& d)
{
	priority_queue<Cell> Q;
	d = VI(n + 1, INF);
	Q.emplace(x, 0);
	d[x] = 0;
	
	int y, w;
	while (!Q.empty())
	{
		auto [x, dist] = Q.top();
		Q.pop();
		
		if (dist > d[x])
			continue;
			
		for (auto node : adj[x])
		{
			y = node.first;
			w = node.second;
			
			if (d[y] > d[x] + w)
			{
				d[y] = d[x] + w;
				Q.emplace(y, d[y]);
			}
		}
	}
}

void ReadInput()
{
	fin >> n >> m >> k;
	
	k++;
	v = VB(k + 1);
	nodes = VI(k + 1);
	adj = VVPI(n + 1);
	
	for (int i = 1; i <= k; ++i)
		fin >> nodes[i];
	nodes[k] = n;
		
	int x, y, w;
	for (int i = 1; i <= m; ++i)
	{
		fin >> x >> y >> w;
		
		adj[x].emplace_back(y, w);
		adj[y].emplace_back(x, w);
	}
}