using System;

public class Program {
	public static void Main() {
		int p1 = int.Parse(Console.ReadLine());
		int p2 = int.Parse(Console.ReadLine());
		int n = int.Parse(Console.ReadLine());
		int c = 0;
		string[] room = new string[n];
		for (int i = 0; i < n; i++) {
			string s = Console.ReadLine();
			if (Array.IndexOf(room, s) != -1) {
				c += p1 + p2;
			}
			room[i] = s;
		}
		Console.WriteLine(c);
	}
}