When programmer Vova was in China he discovered that Russian watches “Zarya” were sold
there ten times cheaper than in Russia. Vova decided to make some money and bought a lot of watches. He wanted to sell them at home at halfprice (that would be five times more expensive than he had paid for them). But when he returned he found out that the watches showed different times; moreover, from a slightest push they stopped (or started to work again). Obviously, they were not real “Zarya” watches, but their exact copies. In order to sell the whole lot as quickly as possible, Vova wants to set them
all at the same time. He then will be able to say that this is the time at the producing plant. Of course, before opening the suitcase he will have to push it a bit to make the watches start to work simultaneously.
In order to set a time on a watch, Vova must rotate the winder. He can make one turn of the winder in one second; as he does so, the secondhand makes a complete circle. When Vova turns the winder, the minutehand rotates 60 times slower than the secondhand,
and the hourhand rotates 12 times slower than the minutehand. For example, to set time six hours ahead it takes six minutes. The hands of the watches can be rotated clockwise only. Help Vova to prepare the watches for sale. Choose a time that should be set on all watches so that the total time Vova spends setting it is minimal.
Input
The first line contains the number n of watches Vova bought
(1 ≤ n ≤ 50000). Then there are n lines. The (i+1)th line of the input contains the time that the ith watch shows, in the format h:mm:ss. Here the integer h (1 ≤ h ≤ 12) is the hour and the twodigit integers mm and ss
(00 ≤ mm, ss ≤ 59) are the minutes and seconds,
respectively.
Output
Output the time that should be set on all watches in the format given above.
Sample
input  output 

3
11:30:00
12:10:01
6:10:18
 12:10:01

Problem Author: Andrey Demidov
Problem Source: ACM ICPC 2007–2008. NEERC. Eastern Subregion. Yekaterinburg, October 27, 2007