#include <bits/stdc++.h>
using namespace std;

inline int read()
{
	int x=0,f=1,c=getchar();
	while(c<48) c=='-'&&(f=-1),c=getchar();
	while(c>47) x=x*10+c-'0',c=getchar();
	return x*f;
}

const int MAXN = 505;
const int INF = 0x3f3f3f3f;
struct Edge {int to,val;};
std::vector<Edge> G[MAXN];
int p[MAXN],inq[MAXN],f[MAXN][MAXN<<3];
int n,m,k; queue<int> q;

inline void addedge(int u,int v,int w)
{
	G[u].push_back(Edge{v,w});
	G[v].push_back(Edge{u,w});
}

inline void spfa(int st)
{
	while(!q.empty())
	{
		int x=q.front(); q.pop(); inq[x]=0;
		for(Edge &e : G[x])
			if(f[e.to][st]>f[x][st]+e.val)
			{
				f[e.to][st]=f[x][st]+e.val;
				if(!inq[e.to]) q.push(e.to),inq[e.to]=1;
			}
	}
}

int main(int argc, char const *argv[])
{
	n=read(),m=read(),k=read();
	memset(f,INF,sizeof(f));
	for(int i=1,x,y; i<=m; ++i)
		x=read(),y=read(),addedge(x,y,read());
	for(int i=1; i<=k; ++i)
		f[p[i]=read()][1<<(i-1)]=0;
	for(int st=0; st<(1<<k); spfa(st),++st)
		for(int i=1; i<=n; ++i)
		{
			for(int t=st; t; t=(t-1)&st)
				f[i][st]=min(f[i][st],f[i][t]+f[i][st^t]);
			if(f[i][st]^INF) q.push(i),inq[i]=1;
		}
	printf("%d",f[p[1]][(1<<k)-1]);
	return 0;
}