import sys
input = lambda :sys.stdin.readline()[:-1]
ni = lambda :int(input())
na = lambda :list(map(int,input().split()))
yes = lambda :print("yes");Yes = lambda :print("Yes");YES = lambda : print("YES")
no = lambda :print("no");No = lambda :print("No");NO = lambda : print("NO")
#######################################################################
n, k, m, p = na()
g = [[]for i in range(n)]
inf = float("inf")
for _ in range(m):
    u,v = na()
    u-=1
    v-=1
    g[u].append(v)
    g[v].append(u)

s = [ni() for i in range(n)]
x = [ni()-1 for i in range(k)]

from heapq import *
hq = []
# 検疫されたか
f = [-1] * n
# いつ感染したか
d = [inf] * n
for i in range(k):
    heappush(hq, (s[x[i]], x[i]))
    d[x[i]] = 0
ans = 0
while hq:
    #print(hq,f,d)
    t, v = heappop(hq)
    if f[v] != -1 and f[v] < t:
        continue
    for u in g[v]:
        if d[u] == inf:
            d[u] = t
            heappush(hq, (t+s[u], u))
        elif t - d[u] < p and f[u] == -1:
            f[u] = t
            ans += 1

print(ans)