mod = 1000000007
eps = 10**-9


def main():
    import sys
    input = sys.stdin.readline
    import heapq

    def dijkstra(adj, start):
        # adj: [[to, cost] * vertices], 0th index must be empty
        inf = 1 << 60
        dist = [inf] * len(adj)
        dist[start] = 0
        q = []
        heapq.heappush(q, (0, start))
        while q:
            min_dist, v_from = heapq.heappop(q)
            if min_dist > dist[v_from]:
                continue
            v_tos = adj[v_from]
            for v_to, cost in v_tos:
                if min_dist + cost < dist[v_to]:
                    dist[v_to] = min_dist + cost
                    heapq.heappush(q, (dist[v_to], v_to))
        return dist

    N, M, K = map(int, input().split())
    R = list(map(int, input().split()))

    idx = {r: i for i, r in enumerate(R)}
    adj = [[] for _ in range(N * (1 << K) + 1)]
    for i in range(1, M+1):
        a, b, c = map(int, input().split())
        if i not in idx:
            for state in range(1 << K):
                aa = a + state * N
                bb = b + state * N
                adj[aa].append((bb, c))
                adj[bb].append((aa, c))
        else:
            j = idx[i]
            for state in range(1 << K):
                aa = a + state * N
                bb = b + state * N
                state_new = state | (1 << j)
                aaa = a + state_new * N
                bbb = b + state_new * N
                adj[aa].append((bbb, c))
                adj[bb].append((aaa, c))

    dist = dijkstra(adj, 1)
    print(dist[-1])


if __name__ == '__main__':
    main()