package com.company.More;

import java.util.Scanner;

public class WeddingSeats {
    public static void main(String[] args) {
        Scanner scanner = new Scanner(System.in);

        String sector = scanner.nextLine();
        int firstSectorSeats = Integer.parseInt(scanner.nextLine()) - 1;
        int oddSeats = Integer.parseInt(scanner.nextLine());
        int oddSeatsReset = oddSeats;

        char sectorChar = sector.charAt(0);

        int counter = 0;

        for (char i = 'A' ; i <= sectorChar ; i++) {
            firstSectorSeats++;
            for (int j = 1; j <= firstSectorSeats ; j++) {
                if (j % 2 == 0){
                    oddSeatsReset = (oddSeats * 2);
                } else {
                    oddSeatsReset = oddSeats;
                }
                for (char k = 'a'; k < oddSeatsReset + 'a' ; k++) {

                    System.out.printf("%c%d%c%n",i,j,k);

                    counter++;
                }
            }

        }

        System.out.println(counter);


    }
}