from collections import Counter
p1 = int(input())
p2 = int(input())
n = int(input())
r = [int(input()) for _ in range(n)]
ctr = Counter(r)
ret = 0
for k,v in ctr.items():
    if v==1:
        continue
    ret += (v-1)*(p1+p2)
print(ret)