import random


def encode(msg, pad):
    return msg


def decode(msg, pad):
    return msg


def create_pad(length, width=72):
    chars = _create_chars_for_pad(length)
    lines = _chunk_chars_into_lines(chars, width=width)
    return lines


def _create_chars_for_pad(length):
    chars = []
    for char in range(length):
        chars.append(_AS_ALPHA[random.randint(1, 25)])
    return ''.join(chars)


def _chunk_chars_into_lines(chars, width=72):
    lines = []
    for chunk in _as_line_chunks(chars, width=width):
        lines.append(chunk)
    return '\n\n\n'.join(lines)


def _as_line_chunks(chars, width=72):
    chunk = []
    for char in chars:
        chunk.append(char)
        if len(chunk) == width:
            yield ''.join(chunk)
            chunk = []
    if len(chunk) < width:
        chunk += (['.'] * (width - len(chunk)))
    yield ''.join(chunk)


def _mk_as_alpha():
    as_alpha = dict()
    a_chr = ord('A')
    past_j = False

    for char in range(26):
        letter = chr(a_chr + char)
        if letter != 'J':
            key = char + (1 if not past_j else 0)
            as_alpha[key] = letter
        else:
            past_j = True
    return as_alpha


_AS_ALPHA = _mk_as_alpha()