#include<fstream>
#include<vector>
#include<queue>
#define inf 0x3f3f3f
using namespace std;
ifstream f("ubuntzei.in");
ofstream g("ubuntzei.out");
struct dij
{
	int nod,cost;
};
vector<vector<dij> > a(50002);
vector<int> d(50002,inf);
queue<int> q;
int s=0;
int b[20];
int n,m,i,j,k,p1,p2,p3;
void dijkstra(int x)
{
	int i;
	q.push(x);
	d[1]=0;
	while(!q.empty())
	{
		x=q.front();
		for(i=0;i<a[x].size();++i)
			if(d[a[x][i].nod]>d[x]+a[x][i].cost)
				d[a[x][i].nod]=d[x]+a[x][i].cost,q.push(a[x][i].nod);
		q.pop();
	}
}
int main()
{
	f>>n>>m;
	f>>k;
	for(i=1;i<=k;i++)
		f>>b[i];
	for(i=1;i<=m;i++)
	{
		f>>p1>>p2>>p3;
		a[p1].push_back((dij){p2,p3});
	}
	dijkstra(1);
	g<<d[n];
		return 0;
}