ryoukin = int(input())
hurikae = int(input())

kazu = int(input())

heya = [] #からのリスト用意

for i in range(kazu):
    bangou = int(input())
    heya.append(bangou)

heya.sort()

count = 0

if kazu == 1:
    print(0)

else:
    for k in range(kazu - 1):
        if heya[k] == heya[k+1]:
            count += 1

    print((ryoukin + hurikae) * count)