from heapq import heappop, heappush

n, m, k = map(int, input().split())
R = list(map(int, input().split()))
Rset = set(R)
edge = [[] for _ in range(n + 1)]
for i in range(1, m + 1):
    a, b, c = map(int, input().split())
    edge[a].append((b, c, i))
    edge[b].append((a, c, i))

H = [(0, 1, set())]
while H:
    res, curr, road = heappop(H)
    if road == Rset and curr == n:
        print(res)
        break
    for np, nc, idx in edge[curr]:
        nroad = road.copy()
        if idx in Rset:
            nroad.add(idx)
        heappush(H, (res + nc, np, nroad))