#include <cstdio>
#include <algorithm>
#include <cstring>
#include <vector>
#define maxN 2002
#define maxK 17
#define maxP 32770
#define inf 1000000000
using namespace std;
int n, N[maxP], m, p, i, j, k, c[maxK], H[maxP][maxN], poz[maxP][maxN], f[maxN], d[maxN][maxP];
bool used[maxN][maxP];
vector < pair <int, int> > V[maxN];
inline int father(int nod)
{
    return nod / 2;
}

inline int left_son(int nod)
{
    return nod * 2;
}

inline int right_son(int nod)
{
    return nod * 2 + 1;
}
void sift(int h, int N, int K)
{
    int son;
    do
    {
        son = 0;
        if (left_son(K) <= N)
        {
            son = left_son(K);
            if (right_son(K) <= N && d[H[h][right_son(K)]][h] < d[H[h][left_son(K)]][h])
            {
                son = right_son(K);
            }
            if (d[H[h][son]][h] >= d[H[h][K]][h])
            {
                son = 0;
            }
        }

        if (son)
        {
            swap(poz[h][H[h][K]], poz[h][H[h][son]]);
            swap(H[h][K], H[h][son]);
            K = son;
        }
    }
    while (son);
}
void percolate(int h, int N, int K)
{
    int key = H[h][K];

    while ((K > 1) && (d[key][h] < d[H[h][father(K)]][h]))
    {
        H[h][K] = H[h][father(K)];
        poz[h][H[h][father(K)]] = K;
        K = father(K);
    }

    H[h][K] = key;
    poz[h][key] = K;
}
void cut(int h, int& N, int K)
{
    if (N == K)
    {
        poz[h][H[h][K]] = 0;
        -- N;
        return ;
    }
    H[h][K] = H[h][N];
    poz[h][H[h][N]] = K;
    --N;

    if ((K > 1) && (d[H[h][K]][h] < d[H[h][father(K)]][h]))
    {
        percolate(h, N, K);
    }
    else
    {
        sift(h, N, K);
    }
}
void insert(int h, int& N, int key)
{
    H[h][++ N] = key;
    poz[h][key] = N;
    percolate(h, N, N);
}
void read()
{
    int x, y, z;
    freopen("ubuntzei.in", "r", stdin);
    scanf("%d %d", &n, &m);
    scanf("%d", &k);
    p = 1 << k;
    for (i = 1; i <= k; ++ i)
    {
        scanf("%d", &c[i]);
        f[c[i]] = i;
    }
    for (i = 1; i <= m; ++ i)
    {
        scanf("%d %d %d", &x, &y, &z);
        V[x].push_back(make_pair(y, z));
        V[y].push_back(make_pair(x, z));
    }
}
void solve()
{
    int x, node;
    for (i = 1; i <= n; ++ i)
        for (j = 0; j < p; ++ j)
        {
            d[i][j] = inf;
            poz[j][i] = 0;
        }
    d[1][0] = 0;
    insert(0, N[0], 1);
    for (j = 0; j < p; ++ j)
    {
        while (N[j])
    {
        x = H[j][1];
        used[x][j] = 1;
        cut(j, N[j], 1);
        for (i = 0; i < V[x].size(); ++ i)
            {
                node = V[x][i].first;
                if (!f[node])
                {
                    /*if (used[node][j])
                        continue;*/
                    if (d[node][j] > d[x][j] + V[x][i].second)
                    {
                        d[node][j] = d[x][j] + V[x][i].second;

                        if (poz[j][node])
                            cut(j, N[j], poz[node][j]);
                        insert(j, N[j], node);
                    }
                }
                else
                {
                    int Pow = 1 << (f[node] - 1);
                    /*if (used[node][j + Pow])
                        continue; */
                    if (d[node][j + Pow] > d[x][j] + V[x][i].second)
                    {
                        d[node][j + Pow] = d[x][j] + V[x][i].second;

                        if (poz[j + Pow][node])
                            cut(j + Pow, N[j + Pow], poz[j + Pow][node]);
                        insert(j + Pow, N[j + Pow], node);
                    }
                }

            }
    }
    }
}
void write()
{
    freopen("ubuntzei.out", "w", stdout);
    printf("%d", d[n][p - 1]);
}
int main()
{
    read();
    solve();
    write();
    return 0;
}