sector = input()
row = int(input())
place = int(input()) + 96

counter = 0

for i1 in range(65, ord(sector)+1):
    row += 1
    for i2 in range(1, row):
        if i2 % 2 != 0:
            for i3 in range(97, place+1):
                print(f'{chr(i1)}{i2}{chr(i3)}')
                counter += 1
        else:
            for i3 in range(97, place + 3):
                print(f'{chr(i1)}{i2}{chr(i3)}')
                counter += 1

print(counter)