"""

最短経路かな

他の人に感染させるタイミング昇順に見ればいい？

"""

import heapq
import sys
from sys import stdin

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

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

for i in range(M):

    u,v = map(int,stdin.readline().split())
    u -= 1
    v -= 1

    lis[u].append(v)
    lis[v].append(u)

s = [int(stdin.readline()) for i in range(N)]

q = []
d = [float("inf")] * N

for i in range(K):
    x = int(stdin.readline())-1
    d[x] = 0
    heapq.heappush(q , (s[x] , x) )

ans = 0
fix = [-1] * N

while q:

    cd,v = heapq.heappop(q)

    if fix[v] != -1 and fix[v] < cd:
        continue
    
    for nex in lis[v]:

        if d[nex] == float("inf"):
            d[nex] = cd
            heapq.heappush(q , (cd+s[nex],nex))

        elif cd < d[nex]+P and fix[nex] == -1:
            ans += 1
            d[nex] = -1
            fix[nex] = cd

print (ans)