using System;
using System.Linq;
using System.Collections.Generic;

class Program {
  static void Main() {
    var p1 = int.Parse(Console.ReadLine());
    var p2 = int.Parse(Console.ReadLine());
    var n = int.Parse(Console.ReadLine());
    var dic = new Dictionary<int, int>();
    for (int i = 0; i < n; i++) {
      var r = int.Parse(Console.ReadLine());
      if (dic.ContainsKey(r)) {
        dic[r]++;
      } else {
        dic[r] = 1;
      }
    }
    var ans = 0;
    foreach (var item in dic) {
      if (item.Value > 1) {
        ans += (p1 + p2) * (item.Value - 1);
      }
    }
    Console.WriteLine(ans);
  }
}