## Get Some Time

### Instructions

Create a function `firstDayWeek` that receives a week of the year
(from 1 to 53) and a year (as a string), and returns the first day
of that week, in the format: 'dd-mm-yyyy'. By beginning of the week
we mean the monday of that week.

If the first week is requested and it starts on the previous year
of the presented one, it should return the first day of the year.