b_combinate.py

SYMBOLS = {
    2: 'abc',
    3: 'def',
    4: 'ghi',
    5: 'jkl',
    6: 'mno',
    7: 'pqrs',
    8: 'tuv',
    9: 'wxyz'
}


def create_all_pairs(*seqs):
    if not seqs:
        return [[]]
    else:
        return [[x] + p for x in seqs[0] for p in create_all_pairs(*seqs[1:])]


numbers = list(map(int, input()))
seqs = []
for number in numbers:
    seqs.append(list(SYMBOLS[number]))
result = create_all_pairs(*seqs)
print(' '.join([''.join(index) for index in result]))