import itertools
import collections
import math
def main():
  N,M,X=map(int,input().split( ))
  A=list(range(N))
  B=list(range(N))
  for num in range(N):
    A[num],B[num]=map(int,input().split( ))
  K=int(input())
  S=list(range(N))
  T=list(range(N))
  C= [int(i) for i in input().split()]
  Q=list(itertools.permutations(T))
  F=list(range(math.factorial(N)))
  U=list(range(K))
  E=0
  for j in range(K):
    if C[j]==0:
      U[j]=0
    else:
     for num in range(math.factorial(N)):
      for p in range(N):
        T[p] = B[Q[num][p]]
      for NUM in range(C[j]):
        E=E + A[Q[num][NUM]]
      F[num]=E + len(collections.Counter(T[0:C[j]])) * X
      E=0
      U[j]= max(F)
  h=0
  for w in range(K):
    h=h + U[w]
  print(h)  
if __name__ == '__main__':
  main()