#!/usr/bin/env python3
#
#       This program is free software; you can redistribute it and/or modify
#       it under the terms of the GNU General Public License as published by
#       the Free Software Foundation; either version 3 of the License, or
#       (at your option) any later version.
#
#       This program is distributed in the hope that it will be useful,
#       but WITHOUT ANY WARRANTY; without even the implied warranty of
#       MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
#       GNU General Public License for more details.
#
#       You should have received a copy of the GNU General Public License
#       along with this program; if not, write to the Free Software
#       Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston,
#       MA 02110-1301, USA.

from sys import argv

def get_argv():
    class ScaleError(Exception): pass
    class RangeError(Exception): pass
    if len(argv) < 3:
        print("Usage: {0} 00:00 m|am|pm".format(argv[0]))
        exit()
    try:
        part = argv[2].lower()
        if not part in {"m", "am", "pm"}:
            raise ScaleError("unknown scale '{0}', use 'm (military)', 'am' or 'pm'.".format(part))
        time = argv[1].split(":")
        hour = int(time[0])
        max = 23 if part == "m" else 12
        min = 0 if part == "m" else 1
        if not (min <= hour <= max):
            raise RangeError("{0} hour(s) does not fall within {1} to {2}".format(hour, min, max))
        minute = int(time[1])
        if not (0 <= minute < 60):
            raise RangeError("{0} minute(s) does not fall within 0 to 59".format(minute))
    except (ValueError, RangeError, ScaleError) as err:
        print("Error:", err)
        exit()
    return hour, minute, part

def military_to_standerd(hour):
    if hour == 0:
        h = 12
        part = "am"
    if hour == 12:
        h = 12
        part = "pm"
    elif hour > 12:
        h = hour - 12
        part = "pm"
    else:
        h = hour
        part = "am"
    return h, part

def standerd_to_military(hour, part):
    if hour == 12 and part == "am":
        h = 0
    elif hour == 12 and part == "pm":
        h = 12
    elif part in "pm":
        h = hour + 12
    else:
        h = hour
    return h

def main():
    hour, minute, part = get_argv()
    if part in "m":
        hour, part = military_to_standerd(hour)
        p = "{0}:{1} {2}" if len(str(minute)) == 2 else "{0}:0{1} {2}"
        print(p.format(hour, minute, part))
    elif part in {"am", "pm"}:
        hour = standerd_to_military(hour, part)
        p = "{0}:{1}" if len(str(minute)) == 2 else "{0}:0{1}"
        p = p if len(str(hour)) == 2 else "0{0}".format(p)
        print(p.format(hour, minute))

if __name__ == "__main__":
    main()