#!/usr/bin/python

def basen (base, num):
    q = num / base
    r = num % base

    if q == 0:
        return [r]
    else:
        return basen(base, q) + [r]

def choose (list, number):
    iterations = len(list)**number

    for i in range(0, iterations):
        choice = basen(len(list), i)

        while len(choice) < number:
            choice.insert(0, 0)

        yield [ list[x] for x in choice ]

digit_letters = { 2: [ 'a', 'b', 'c' ],
                  3: [ 'd', 'e', 'f' ],
                  4: [ 'g', 'h', 'i' ],
                  5: [ 'j', 'k', 'l' ],
                  6: [ 'm', 'n', 'o' ],
                  7: [ 'p', 'r', 's' ],
                  8: [ 't', 'u', 'v' ],
                  9: [ 'w', 'x', 'y' ] }

letter_choices = []

for letters in choose([0,1,2], 4):
    letter_choices.append(letters)

for digits in choose(range(2,10), 4):
    for letters in letter_choices:
        word = []

        for i in range(0, len(digits)):
            digit    = digits[i]
            letter_i = letters[i]
            letter   = digit_letters[digit][letter_i]

            word.append(letter)

        print digits, ":", ''.join(word)