The division times of virus A: 2 * 2 * 2 *(20 times) = 1048576.
Number of times virus B increased: 10/0.5=20 times.
The number of virus B increased: 2 * (20+1) = 420,000.
There are 65438 A viruses+0048576 > 420000 B viruses.
Remaining quantity of virus A and virus B after cancellation: 420000- 1048576=(-628576).