I have a number of roses for sale. The first buyer bought half of my roses then I gave him additional one for free. The second buyer bought half of the remaining roses then I gave him additional one also for free. The third buyer also bought half of the remaining roses then I gave him additional one also for free, this time all of my roses has been sold out.

How many roses do I have?

0+1 = 1
*2 = 2
+1 = 3
*2 = 6
+1 = 7
*2 = 14

14 roses