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

namespace ConsoleApp
{
    class Program
    {
        static void Main(string[] args)
        {
            char lastSector = char.Parse(Console.ReadLine());
            int rowsCount = int.Parse(Console.ReadLine());
            int oddRowCount = int.Parse(Console.ReadLine());
            int totalPlaces = 0;
            for (char i1 = 'A'; i1 <= lastSector; i1++, rowsCount++)
            {
                for (int i2 = 1; i2 <= rowsCount; i2++)
                {
                    int places = i2 % 2 == 1 ? oddRowCount : oddRowCount * 2;

                    for (char i3 = 'a'; i3 < 'a'+places; i3++)
                    {
                        Console.WriteLine($"{i1}{i2}{i3}");
                        totalPlaces++;
                    }
                }

            }
            Console.WriteLine(totalPlaces);
        }
    }
}