In a video there are 3 characters A, B and C. A can build a building in 15 days and B can build the same in 30 days while C can destroy the building in 30 days. If, C works every day and A and B work every alternate day starting from A, what is the time required to build the building in the game?
1
59 days
2
29 days
3
39 days
4
49 days
5
None of these