N,M,L,S,E = map(int, input().split())

edge = [[] for i in range(N)]

for i in range(M):
    a,b,t = map(int, input().split())
    a-=1;b-=1
    edge[a].append((b,t))
    edge[b].append((a,t))
toilet = list(map(int, input().split()))

from heapq import heappush, heappop
INF = 10**16
def dijkstra(N, edge, s):
    dist = [INF] * N
    que = [(0, s)]
    dist[s] = 0
    while que:
        c, v = heappop(que)
        if dist[v] < c:
            continue
        for t, cost in edge[v]:
            if dist[v] + cost < dist[t]:
                dist[t] = dist[v] + cost
                heappush(que, (dist[t], t))
    return dist

dist1 = dijkstra(N,edge,0)
dist2 = dijkstra(N,edge,N-1)
#print(dist1)
#print(dist2)
st,en = S,S+E-1
#print(st,en)
ans = 10**16
for i in toilet:
    i-=1
    if dist1[i] < st:
        now = st+1
    elif st <= dist1[i] <= en:
        now = dist1[i]+1
    else:
        continue
    if dist2[i] == 10**16:
        continue
    now += dist2[i]
    ans = min(ans,now)
print(ans if ans != 10**16 else -1)