import heapq

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

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

for i in range(M):
    u,v = map(int, input().split())
    u -= 1
    v -= 1
    adj[u].append(v)
    adj[v].append(u)

s = [int(input()) for _ in range(N)]

infected = [-1 for _ in range(N)]

todo = []
heapq.heapify(todo)

for i in range(K):
    x = int(input())
    x -= 1
    infected[x] = 0
    heapq.heappush(todo, (s[x], x))

quar = [-1 for _ in range(N)]
answer = 0

while todo:
    x = heapq.heappop(todo)
    if quar[x[1]] != -1 and quar[x[1]] < x[0]: continue
    for u in adj[x[1]]:
        if infected[u] == -1:
            infected[u] = x[0]
            heapq.heappush(todo, (x[0]+s[u], u))
        else:
            if infected[u] + P > x[0] and quar[u] == -1:
                quar[u] = x[0]
                answer += 1

print(answer)