import sys
input = sys.stdin.readline
N, M, X = map(int, input().split())
a = [tuple(map(int, input().split())) for _ in range(N)]

import heapq
hpush = heapq.heappush
hpop = heapq.heappop

h = []
table = [0] * (M + 1)
for x, y in a: hpush(h, (-(x + X), y))

K = int(input())
qs = list(map(int, input().split()))

qc = [0] * (N + 2)
for x in qs: qc[x + 1] -= 1
qc[1] += K
for i in range(N + 1): qc[i + 1] += qc[i]
#print(qc)

res = 0
for i in range(1, N + 1):
  while table[h[0][1]] == 1:
    x, y = hpop(h)
    hpush(h, (x + X, 0))
  x, y = hpop(h)
  if y: table[y] = 1
  x = -x
  res += x * qc[i]
  #print(x, y)
print(res)