#!/usr/bin/env python
# -*- coding: utf-8 -*-
def remove_deplicates(x):
    y = []
    for i in x:
        if i not in y:
            y.append(i)
    return y

yuki_charge = int(input())
furi_charge = int(input())

reserve_count = int(input())
reserve_room = []
c = 0
for i in range(0, reserve_count):
    reserve_room.append(int(input()))
room_collection = remove_deplicates(reserve_room)
for room in room_collection:
    count_room_res = reserve_room.count(room)
    if count_room_res > 1:
        c += (yuki_charge + furi_charge) * (count_room_res  - 1)
print(c)