Sleepy Sasha is Trouble at the University#17

Problem Author:	Pavlo Tsitsei
Prepared by:	Pavlo Tsitsei, Bohdan Feysa
Tutorial by:	Pavlo Tsitsei

Let's convert all the time into minutes. Then, in a day, there are 1800 minutes, the classes will take $x \cdot 90$ minutes in total, and the homework will take $\sum_{i = 1}^{n} a_{i}$ \sum_{i=1}^n a_i minutes. Therefore, the total remaining time is $1800 - x \cdot 90 - \sum_{i = 1}^{n} a_{i}$ 1800-x\cdot 90-\sum_{i=1}^n a_i. If the answer is negative, then -1 should be output. Otherwise, the output should be the number of hours and minutes, which is the total number of minutes divided by 60 and the remainder of the division by 60.