#include<fstream>
#include<algorithm>
#include<vector>
using namespace std;

int n,m,k,i,j,t,a[2002][2002],x,y,ct,uz[2002],s[2002],minn=2000000000,aux,pc,pf;
vector <int> c;

ifstream f("ubuntzei.in");
ofstream g("ubuntzei.out");

int main()
{
    f>>n>>m;
    f>>k;
    for(i=1;i<=k;i++)
    {
        f>>x;
        c.push_back(x);
    }

    for(i=1;i<=n;i++)
    for(j=1;j<=n;j++)
        a[i][j]=1000000000;
    for(i=1;i<=n;i++)
        a[i][i]=0;

    for(i=1;i<=m;i++)
    {
        f>>x>>y>>ct;
        a[x][y]=ct;
        a[y][x]=ct;
    }

    for(t=1;t<=n;t++)
    {
        for(i=1;i<=n;i++)
        for(j=1;j<=n;j++)
            if(a[i][j]>a[i][t]+a[t][j]) a[i][j]=a[i][t]+a[t][j];
    }

    if(k>0)
    {
		sort(c.begin(),c.end());
		pc=1;
		pf=n;
		minn=2000000000;
		do
        {
			aux=a[pc][c.front()]+a[c.back()][pf];

			for(i=0;i<(int)c.size()-1;i++)
				aux+=a[c[i]][c[i+1]];

			minn=min(minn,aux);
		} while(next_permutation(c.begin(),c.end()));

		g<<minn<<"\n";
	}
	else
		g<<a[1][n]<<"\n";

    f.close();
    g.close();
    return 0;
}