units = ['', 'one ', 'two ', 'three ', 'four ', 'five ', 'six ', 'seven ', 'eight ',
         'nine ', 'ten ', 'eleven ', 'twelve ', 'thirteen ', 'fourteen ', 'fifteen ',
         'sixteen ', 'seventeen ', 'eighteen ', 'nineteen ']
tens = ['twenty ', 'thirty ', 'forty ', 'fifty ']

def min_str(mins):
    if mins < 20:
        return (0 < mins < 10) * 'oh ' + units[mins]
    else:
        q, r = divmod(mins, 10)
        return tens[q-2] + min_str(r)[3:]

def time_to_words(timestr):
    hr, mins = map(int, timestr.split(':'))
    outstr = "It's " + (units[hr%12] or 'twelve ') + min_str(mins)
    outstr += 'am' if hr < 12 else 'pm'
    return outstr

for x in ['00:00', '01:30', '12:05', '14:01', '20:29', '21:00']:
    print time_to_words(x)