#CCC16J4. Arrival Time
Arrival Time
Fiona commutes to work each day. If there is no rush-hour traffic, her commute time is 2 hours. However, there is often rush-hour traffic. Specifically, rush-hour traffic occurs from 07:00
(7am) until 10:00
(10am) in the morning and 15:00
(3pm) until 19:00
(7pm) in the afternoon. During rush-hour traffic, her speed is reduced by half.
She leaves either on the hour (at XX:00
), 20 minutes past the hour (at XX:20
), or 40 minutes past the hour (at XX:40
).
Given Fiona's departure time, at what time does she arrive at work?
Input Specification
The input will be one line, which contains an expression of the form HH:MM
, in which HH
is one of the 24 starting hours (00
, 01
, ..., 23
) and MM
is one of the three possible departure minute times (00
, 20
, 40
).
Output Specification
Output the time of Fiona's arrival, in the form HH:MM
.
Sample Input 1
05:00
Output for Sample Input 1
07:00
Explanation for Output for Sample Input 1
Fiona does not encounter any rush-hour traffic, and leaving at 5am, she arrives at exactly 7am.
Sample Input 2
07:00
Output for Sample Input 2
10:30
Explanation for Output for Sample Input 2
Fiona drives for 3 hours in rush-hour traffic, but only travels as far as she normally would after driving for 1.5 hours. During the final 30 minutes (0.5 hours) she is driving in non-rush-hour traffic.
Sample Input 3
23:20
Output for Sample Input 3
01:20
Explanation for Output for Sample Input 3
Fiona leaves at 11:20pm, and with non-rush-hour traffic, it takes two hours to travel, so she arrives at 1:20am the next day.