#define _CRT_SECURE_NO_WARNINGS
#include <string>
#include <vector>
#include <algorithm>
#include <numeric>
#include <set>
#include <map>
#include <queue>
#include <iostream>
#include <sstream>
#include <cstdio>
#include <cmath>
#include <ctime>
#include <cstring>
#include <cctype>
#include <cassert>
#include <limits>
#include <functional>
#define rep(i,n) for(int (i)=0;(i)<(int)(n);++(i))
#define rer(i,l,u) for(int (i)=(int)(l);(i)<=(int)(u);++(i))
#define reu(i,l,u) for(int (i)=(int)(l);(i)<(int)(u);++(i))
#if defined(_MSC_VER) || __cplusplus > 199711L
#define aut(r,v) auto r = (v)
#else
#define aut(r,v) typeof(v) r = (v)
#endif
#define each(it,o) for(aut(it, (o).begin()); it != (o).end(); ++ it)
#define all(o) (o).begin(), (o).end()
#define pb(x) push_back(x)
#define mp(x,y) make_pair((x),(y))
#define mset(m,v) memset(m,v,sizeof(m))
#define INF 0x3f3f3f3f
#define INFL 0x3f3f3f3f3f3f3f3fLL
using namespace std;
typedef vector<int> vi; typedef pair<int,int> pii; typedef vector<pair<int,int> > vpii;
typedef long long ll; typedef vector<long long> vl; typedef pair<long long,long long> pll; typedef vector<pair<long long,long long> > vpll;
typedef vector<string> vs; typedef long double ld;
template<typename T, typename U> inline void amin(T &x, U y) { if(y < x) x = y; }
template<typename T, typename U> inline void amax(T &x, U y) { if(x < y) x = y; }

int main() {
	int N, M, T;
	scanf("%d%d%d", &N, &M, &T);
	vector<vector<int> > g(N, vector<int>(N, INF));
	rep(i, N)
		g[i][i] = 0;
	rep(i, M) {
		int a, b, c;
		scanf("%d%d%d", &a, &b, &c), -- a, -- b;
		amin(g[a][b], c);
		amin(g[b][a], c);
	}
	rep(k, N) rep(i, N) rep(j, N)
		amin(g[i][j], g[i][k] + g[k][j]);
	vi required(T);
	vector<bool> important(N, false);
	rep(i, T) {
		int v;
		scanf("%d", &v), -- v;
		required[i] = v;
		important[v] = true;
	}
	vi steiners;
	rep(i, N) if(!important[i])
		steiners.push_back(i);

	int X = steiners.size();
	int ans = INF;

	if(T >= 16) {
		vector<int> vertices;
		rep(use, 1 << X) {
			vertices = required;
			rep(i, X) if(use >> i & 1)
				vertices.push_back(steiners[i]);
			int V = vertices.size();
			vector<bool> vis(V, false);
			vector<int> cost(V, INF);
			int totalcost = 0;
			cost[0] = 0;
			rep(k, V) {
				pii p(INF, -1);
				rep(i, V) if(!vis[i])
					amin(p, mp(cost[i], i));
				int i = p.second, v = vertices[i];
				vis[i] = true;
				totalcost += cost[i];
				rep(j, V)
					amin(cost[j], g[v][vertices[j]]);
			}
			amin(ans, totalcost);
		}
	}else {
		vector<int> dp((1 << T) * N, INF);

		rep(p, T) rep(q, N)
			dp[(1 << p) * N + q] = g[required[p]][q];

		rep(S, 1 << T) {
			if(!(S & (S-1))) continue;
			rep(p, N) for(int E = (S-1) & S; E > 0; (-- E) &= S) {
				amin(dp[S * N + p], dp[E * N + p] + dp[(S - E) * N + p]);
			}
			rep(p, N) rep(q, N)
				amin(dp[S * N + p], dp[S * N + q] + g[p][q]);
		}

		int U = (1 << T) - 1;
		rep(S, 1 << T) rep(q, N)
			amin(ans, dp[S * N + q] + dp[(U - S) * N + q]);
	}
	printf("%d\n", ans);
	return 0;
}