#include <cstdio>
#include <cstring>
#include <vector>
#include <queue>

const int INF = 2e9;
const int MAXN = 2e3;
#define MAXK 15

struct Edge {
  int node, cost;
  bool operator <(const Edge &aux) const {
    return cost > aux.cost;
  }
};

int v[MAXK], dp[(1 << MAXK)][MAXK], dist[MAXN + 1][MAXN + 1], d[MAXN + 1];
std::vector <Edge> g[MAXN + 1];
std::priority_queue <Edge> heap;

inline void dijkstra(int u, int n) {
  int x;
  for (int i = 1; i <= n; ++i) {
    d[i] = INF;
  }
  d[u] = 0;
  heap.push({u, 0});
  while (!heap.empty()) {
    x = heap.top().node;
    heap.pop();
    for (auto i: g[x]) {
      if (d[x] + i.cost < d[i.node]) {
        d[i.node] = d[x] + i.cost;
        heap.push({i.node, d[i.node]});
      }
    }
  }
  for (int i = 1; i <= n; ++i) {
    dist[u][i] = d[i];
  }
}

inline int min(int a, int b) {
  return a > b ? b : a;
}

int main() {
  int n, m, k, x, y, c, ans;
  FILE *f = fopen("ubuntzei.in", "r");
  fscanf(f, "%d%d%d", &n, &m, &k);
  for (int i = 0; i < k; ++i) {
    fscanf(f, "%d", &v[i]);
  }
  for (int i = 0; i < m; ++i) {
    fscanf(f, "%d%d%d", &x, &y, &c);
    g[x].push_back({y, c});
    g[y].push_back({x, c});
  }
  fclose(f);
  dijkstra(1, n);
  f = fopen("ubuntzei.out", "w");
  if (!k) {
    fprintf(f, "%d\n", dist[1][n]);
  } else {
    for (int i = 0; i < k; ++i) {
      dijkstra(v[i], n);
    }
    for (int i = 1; i < (1 << k); ++i) {
      for (int j = 0; j < k; ++j) {
        dp[i][j] = INF;
      }
    }
    for (int i = 0; i < k; ++i) {
      dp[1 << i][i] = dist[1][v[i]];
    }
    for (int i = 1; i < (1 << k); ++i) {
      for (int j = 0; j < k; ++j) {
        if (i & (1 << j)) {
          for (int p = 0; p < k; ++p) {
            if (i & (1 << p) && j != p) {
              dp[i][j] = min(dp[i][j], dp[i - (1 << j)][p] + dist[v[j]][v[p]]);
            }
          }
        }
      }
    }
    ans = INF;
    for (int i = 0; i < k; ++i) {
      ans = min(ans, dp[(1 << k) - 1][i] + dist[v[i]][n]);
    }
    fprintf(f, "%d\n", ans);
  }
  fclose(f);
  return 0;          
}