from collections import defaultdict
import heapq as hq
N, M, K = map(int, input().split())
R = list(map(int, input().split()))
Edge = [list(map(int, input().split())) for _ in range(M)]

graph = defaultdict(list)
for i in range(M):
    a, b, c = Edge[i]
    d = -1
    if i+1 in R:
        d = R.index(i+1)
    graph[a].append([b, c, d])
    graph[b].append([a, c, d])

INF = 10**18
dist = [INF]*(1 << 13)
dist[1] = 0
task = [1]
mask = (1 << 13)-1
msks = (1 << 8)-1
while task:
    t = hq.heappop(task)
    d = t >> 13
    x = t & mask
    if d > dist[x]:
        continue
    v = x & msks
    s = x >> 8
    for u, c, f in graph[v]:
        ns = (s << 8)+u
        if f >= 0:
            ns |= 1 << (f+8)
        if dist[ns] > d+c:
            dist[ns] = d+c
            hq.heappush(task, ns+((d+c) << 13))

print(dist[(((1 << K)-1) << 8)+N])