from collections import Counter

p1 = int(input())
p2 = int(input())
N = int(input())
room_no = [input() for i in range(N)]
count = Counter(room_no)

lost_sum = []

for k,v in count.items():
    if count[k] != 1:
        lost = (v - 1) * (p1 + p2)
        lost_sum.append(lost)

print(sum(lost_sum))