from heapq import heappush, heappop

N,K,M,P = list(map(int,input().split()))
e_list = [[] for i in range(N)]

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

S = [int(input()) for i in range(N)]

state = [0]*N

q = []

def I(t, mode, v):
    return t * (10**7) + v + (10**6)*(mode=="viral")

def J(i):
    t =  i//(10**7)
    i -= t*(10**7)
    x = i%(10**6)
    i -= x
    if i==0:
        mode = "cure"
    else:
        mode = "viral"
    return t, mode, x

for i in range(K):
    x = int(input()) - 1
    heappush(q, I(0,"viral",x))
    heappush(q, I(P,"cure",x))

while q:
    #print(state)
    t, st, v = J(heappop(q))
    if st == "viral":
        if state[v] == 0:
            state[v] = 1
            for v1 in e_list[v]:
                if state[v1] <= 1:
                    heappush(q, I(t + S[v], "viral", v1))
                    heappush(q, I(t + S[v] + P, "cure", v1))
        elif state[v] == 1:
            state[v] = 2
        elif state[v] >= 2:
            pass
    else:
        if state[v] == 1:
            state[v] = 3
#print(state)
count = 0
for i in range(N):
    if state[i] == 2:
        count += 1
print(count)