

Longest NapAs you may already know, there are professors very busy with a filled schedule of work during the day. Your professor, let's call him Professor P, is a bit lazy and wants to take a nap during the day, but as his schedule is very busy, he doesn't have a lot of chances of doing this. He would REALLY like, however, to take one nap every day. Because he'll take just one nap, he wants to take the longest nap that is possible given his schedule. He decided to write a program to help him in this task but, as we said, Professor P is very lazy. So, he finally decided that YOU must write the program! Input SpecificationThe input will consist of an arbitrary number of test cases, each test case represents one day. The first line of each set contains a positive integer s (not greater than 100) representing the number of scheduled appointments during that day. In the next s lines there are the appointments in the following format:
Where time1 represents the time when the appointment starts and time2 the time it ends. All times will be in the hh:mm format, time1 will always be strictly less than time2, they will be separated by a single space, and all times will be greater than or equal to 10:00 and less than or equal to 18:00. So, your response must be in this interval as well (i.e., no nap can start before 10:00 and last after 18:00). The appointment can be any sequence of characters, but will always be in the same line. You can assume that no line will be longer than 255 characters, that 10 ≤ hh ≤ 18 and that 0 ≤ mm < 60. You CAN'T assume, however, that the input will be in any specific order. You must read the input until you reach the end of file. Output SpecificationFor each test case, you must print the following line:
Where d stands for the number of the test case (starting from 1) and hh:mm is the time when the nap can start. To display the duration of the nap, follow these simple rules:
Notice that you don't have to worry about concordance (i.e., you must print
“ If there is more than one longest nap with the same duration, print the earliest one. You can assume that there won't be a day all busy (i.e., you may assume that there will be at least one possible nap). Sample Input
Output for Sample Input


University of Debrecen; Faculty of Informatics; v. 03/01/2019 