p1 = gets.to_i # 宿泊料金
p2 = gets.to_i # 振替先宿泊料金
n = gets.to_i # 予約件数
sum = 0 #料金合計
roomNumber = Array.new
count = Hash.new(0)

n.times do |i|
    roomNumber[i] = gets.chomp
end

roomNumber.each do |elem|
    count[elem] += 1
end

count.each do |k, v|
    if v > 1
        sum += (v - 1)
    end
end

sum = (p1 + p2) * sum
puts sum