using namespace std;

#include <vector>
#include <bitset>
#include <queue>

#define pb push_back
#define f first
#define s second
#define II inline
#define FOR(i,a,b) for(int i=a;i<=b;++i)
#define CC(v) memset((v),0,sizeof((v)))
#define CP(v,w) memcpy((v),(w),sizeof((w)))
#define mp make_pair

#define IN  "team.in"
#define OUT "team.out"
#define P_MAX 1<<6
#define N_MAX 1<<9
#define oo 1684300900

typedef vector<int> VI;
typedef pair<int,int> pi;

int P,N,M;
int V[P_MAX],Dist[N_MAX],C[N_MAX][N_MAX],D[N_MAX][P_MAX][P_MAX];
vector<pi> A[N_MAX];

II void scan()
{
	freopen(IN,"r",stdin);
	freopen(OUT,"w",stdout);
	scanf("%d%d%d",&P,&N,&M);
	
	int x,y,c;
	FOR(i,1,M)
	{
		scanf("%d%d%d",&x,&y,&c);
		A[x].pb( mp(y,c) );
		A[y].pb( mp(x,c) );
	}
}

struct comp{ bool operator() (int i,int j) {return Dist[i] > Dist[j];} }; 
priority_queue<int,VI,comp> Q;

II void Dijkastra(int S)
{
	memset(Dist,100,sizeof(Dist));
	bool viz[N_MAX] = {0};
	Dist[S] = 0;
	viz[S] = true;
	Q.push(S);
	
	for(int nod;!Q.empty();)
	{
		nod = Q.top();
		Q.pop();
		viz[nod] = false;
		
		for(vector<pi>::iterator it=A[nod].begin();it != A[nod].end();++it)
			if(Dist[it->f] > Dist[nod] + it->s)
			{
				Dist[it->f] = Dist[nod] + it->s;
				if(!viz[it->f])
				{
					viz[it->f] = true;
					Q.push(it->f);
				}	
			}	
	}	
	CP(C[S],Dist);
}

II int sol(int nod,int st,int dr)
{
	if(st > dr)
		return 0;
	if(D[nod][st][dr] != oo)
		return D[nod][st][dr];
		
	int rez(oo);
	FOR(i,st,dr)
		rez = min(rez,sol(V[i],st,i-1) + sol(V[i],i+1,dr) + C[nod][ V[i] ]);
	
	return (D[nod][st][dr] = rez);
}

II void solve()
{
	memset(D,100,sizeof(D));
	memset(C,100,sizeof(C));
	
	FOR(i,1,P)
	{
		scanf("%d",V+i);
		Dijkastra(V[i]);
	}
	Dijkastra(1);
	
	printf("%d\n",sol(1,1,P) );	
}

int main()
{
	scan();
	solve();
	return 0;
}