p1 = int(input())
p2 = int(input())
n = int(input())

book_room = set()
go_back = 0

for __ in range(n):
    room_number = input()  # str
    if room_number in book_room:
        go_back += 1
        continue
    book_room.add(room_number)

print((p1 + p2) * go_back)