P1 = int(input().strip())
P2 = int(input().strip())
N = int(input().strip())

lst1 = []
lst2 = []

for i in range(N):
  R = input().strip()
  try:
    tmp = lst1.index(R)
    lst2[tmp] += 1
  except:
    lst1.append(R)
    lst2.append(1)

print((sum(lst2) - len(lst2)) * (P1 + P2))