import collections

yuki_money = int(input())
another_money = int(input())
n = int(input())
r_list = [int(input()) for i in range(n)]

r_clc = collections.Counter(r_list)
c = 0

for cur_key in r_clc.keys():
    rsv = r_clc[cur_key]
    c += (yuki_money + another_money) * (rsv - 1)
    
res = c

print(res)