using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Threading.Tasks;

class Scanner
{
    private readonly char Separator = ' ';
    private int Index = 0;
    private string[] Line = new string[0];
    public string Next()
    {
        if (Index >= Line.Length)
        {
            Line = Console.ReadLine().Split(Separator);
            Index = 0;
        }
        var ret = Line[Index];
        Index++;
        return ret;
    }

    public int NextInt()
    {
        return int.Parse(Next());
    }

    public long NextLong()
    {
        return long.Parse(Next());
    }

    public string[] StringArray()
    {
        Line = Console.ReadLine().Split(Separator);
        Index = Line.Length;
        return Line;
    }

    public int[] IntArray()
    {
        var l = StringArray();
        var res = new int[l.Length];
        for (int i = 0; i < l.Length; i++)
        {
            res[i] = int.Parse(l[i]);
        }
        return res;
    }

    public long[] LongArray()
    {
        var l = StringArray();
        var res = new long[l.Length];
        for (int i = 0; i < l.Length; i++)
        {
            res[i] = long.Parse(l[i]);
        }
        return res;
    }
}
class Program
{
    private int P1, P2, N;
    private int[] R;
    private void Scan()
    {
        var sc = new Scanner();
        P1 = sc.NextInt();
        P2 = sc.NextInt();
        N = sc.NextInt();
        R = new int[N];
        for (int i = 0; i < N; i++)
        {
            R[i] = sc.NextInt();
        }
    }

    public void Solve()
    {
        Scan();
        var map = new Dictionary<int, int>();
        foreach (int i in R)
        {
            int o;
            if (!map.TryGetValue(i, out o))
            {
                o = 0;
            }
            map[i] = o + 1;
        }
        int ans = 0;
        foreach (var i in map)
        {
            ans += (P1 + P2) * (i.Value - 1);
        }
        Console.WriteLine(ans);
    }

    static void Main(string[] args)
    {
        new Program().Solve();
    }
}