#P15521. [CCC 2016 J4] Arrival Time
[CCC 2016 J4] Arrival Time
Description
Fiona commutes to work each day. If there is no rush-hour traffic, her commute time is hours. However, there is often rush-hour traffic. Specifically, rush-hour traffic occurs from (7am) until (10am) in the morning and (3pm) until (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 Format
The input will be one line, which contains an expression of the form HH:MM, where HH is one of the 24 starting hours (, , ..., ) and MM is one of the three possible departure minute times (, , ).
Output Format
Output the time of Fiona's arrival, in the form HH:MM.
05:00
07:00
07:00
10:30
23:20
01:20
Hint
Explanation for Output for Sample Input 1
Fiona does not encounter any rush-hour traffic, and leaving at am, she arrives at exactly am.
Explanation for Output for Sample Input 2
Fiona drives for hours in rush-hour traffic, but only travels as far as she normally would after driving for hours. During the final minutes ( hours) she is driving in non-rush-hour traffic.
Explanation for Output for Sample Input 3
Fiona leaves at pm, and with non-rush-hour traffic, it takes two hours to travel, so she arrives at am the next day.
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