"""

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
state = [0] * N

# 0=未感染
# 1=観戦
# 2=検疫

for i in range(K):

    x = int(stdin.readline())-1
    d[x] = 0
    heapq.heappush(q , (d[x]+s[x] , x) )

ans = 0
second_time = [-1] * N

while q:

    itime,v = heapq.heappop(q)
    if itime != d[v] + s[v]:
        continue

    if state[v] == 2 and second_time[v] > itime:
        continue

    
    for nex in lis[v]:

        if d[nex] > d[v] + s[v]:
            d[nex] = d[v] + s[v]
            state[nex] = 1
            heapq.heappush( q , (d[nex]+s[nex] , nex) )

        elif state[nex] == 1 and d[nex] + P > d[v]+s[v]:
            state[nex] = 2
            second_time[nex] = max(second_time[nex] , d[v]+s[v])

ans = 0
for i in range(N):
    if state[i] == 2:
        ans += 1

print (ans)