#include <cstdio>
#include <vector>
#include <set>
#include <climits>
#define DIM 2100
#define INF 0x3f3f3f3f
using namespace std;

long n, m, k;
vector<pair<long,long> > G[DIM];
long f[DIM];
long dest[DIM], pl[DIM];
vector<vector<long> > c;
long x[DIM];
bool s[DIM];
long sol(INF);

set<pair<long,long> > T;
long d[DIM];

void Perm(int k);
void Dijkstra(long root);
void Ver();

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", &f[i]);
	int x, y, cost;
	for (int i = 1; i <= m; ++i)
	{
		scanf("%d %d %d", &x, &y, &cost);
		G[x].push_back(make_pair(y,cost));
		G[y].push_back(make_pair(x,cost));
	}
	if (k == 0)
	{
		Dijkstra(1);
		printf("%ld\n", d[n]);
	}
	else
	{
		c.resize(n+1);
		for (int i = 1; i <= n; ++i) c[i].resize(n+1);
		for (int i = 1; i <= k; ++i)
		{
			Dijkstra(f[i]);
			pl[i] = d[1];
			dest[i] = d[n];
			for (int j = 1; j <= k; ++j)
				c[i][j] = d[f[j]];
		}
		/*for (int i = 1; i <= k; ++i)
		{
			//for (int j = 1; j <= k; ++j)
				printf("%d ", pl[i]);
			printf("\n");
		}*/
		Perm(1);
		printf("%ld\n", sol);
	}
	fclose(stdin);
	fclose(stdout);
	return 0;
}

void Dijkstra(long root)
{
	for (int i = 1; i <= n; ++i)
		d[i] = INF;
	d[root] = 0;
	T.insert(make_pair(0, root));
	
	set<pair<long,long> >::iterator it;
	while (!T.empty())
	{
		it = T.begin();
		int nod = it->second;
		//int val = it->first; // == d[nod]
		T.erase(it);
		for (int i = 0; i < (int) G[nod].size(); ++i)
		{
			int son = G[nod][i].first;
			int vv = G[nod][i].second;
			if (d[son] > d[nod] + vv)
			{
				d[son] = d[nod] + vv;
				T.insert(make_pair(d[son], son));
			}
		}
	}
}

void Perm(int y)
{
	if (y == k + 1)
	{
		Ver();
		return;
	}
	for (int i = 1; i <= k; ++i)
	{
		x[y] = i;
		if (!s[i])
		{
			s[i] = 1;
			Perm(y+1);
			s[i] = 0;
		}
	}
}

void Ver()
{
	
	long nr = 0;
	nr += pl[x[1]];
	for (int i = 1; i < k; ++i)
		nr += c[x[i]][x[i+1]];
	nr += dest[x[k]];
	if (nr < sol) sol = nr;
}