import collections

yuki_Hotel = int(input())
next_Hotel = int(input())
n = int(input())
Hotels = []
price = 0

for count in range(n):
    list = input()
    Hotels.append(list)

c = collections.Counter(Hotels)
for hotel in Hotels:
    if c[hotel] >= 2:
        price += (c[hotel] * yuki_Hotel) + (c[hotel] * next_Hotel)
print(price)