using System;
using System.Collections.Generic;
public class Hello{
    public static void Main(){
        int price1 = int.Parse(Console.ReadLine());
        int price2 = int.Parse(Console.ReadLine());
        var loss = price2 + price1;
        
        int N = int.Parse(Console.ReadLine());
        var room = new HashSet<int>();
        for(int x = 0;x < N;x++){
            int input = int.Parse(Console.ReadLine());
            room.Add(input);
        }
        var ans = loss * (N - room.Count);
        Console.WriteLine(ans);
        
    }
}