Cake#1949
On his birthday, Peter bought a beautiful and delicious cake with a perfectly round shape. Peter did not know how many guests would come to his birthday, so he had to develop an algorithm to quickly cut the cake into equal pieces. Cuts can be made either along the radius or the diameter.
Help Peter solve this problem by determining the minimum number of cuts needed to divide the cake into equal parts for a given number of guests.
The input contains one natural number (n \leq 1000), the number of guests, including Peter himself.
Print the minimum possible number of cuts needed to divide the cake.
Example 1
Example 2