using System;

namespace ConsoleApp4
{
    class Program
    {
        static void Main(string[] args)
        {
            char sector = char.Parse(Console.ReadLine());
            int firstSector = int.Parse(Console.ReadLine());
            int place = int.Parse(Console.ReadLine());

            int count = 0;

            for (char i = 'A'; i <= sector; i++)
            {
                for (int j = 1; j <= firstSector; j++)
                {
                    int places = place;

                    if (j % 2 == 0)
                    {
                        places += 2;
                    }

                    for (int k = 0; k < places; k++)
                    {
                        Console.WriteLine($"{i}{j}{(char)(97 + k)}");
                        count++;
                    }
                }

                firstSector++;
            }

            Console.WriteLine(count);
        }
    }
}